android app on kitkat works on lollipop don't : i'm asking to you some help beacause i can't find the solution.
i'm doing an android app and i have decided to add in my app the contact list.
i have take this from google android developpers 
http://developer.android.com/training/contacts-provider/retrieve-names.html
and i have take the code and add all the features to my app(xml/layout/images/javacode etc)
and in my main activity i call the contactlist activity.
if i attack my cellular phone with kitkat 4.4.2 via debug on android studio my app comes and in mymain activity when i call the contacts activity it does so well...
but if i attack my cellular phone with lollipop 5.1.1 when i call the contacts activity it does so well the titlebar is hide and then when i click one contact the app crashes...

it crashes at this instruction

    if (Utils.hasHoneycomb()) {
                    // Enables action bar "up" navigation
                    getActionBar().setDisplayHomeAsUpEnabled(true);
                    
    
                }

and it give to me

    02-18 13:41:15.304 31435-31435/todonotes.com.todonotes_buildfinale E/AndroidRuntime: FATAL EXCEPTION: main
                                                                                         Process: todonotes.com.todonotes_buildfinale, PID: 31435
                                                                                         java.lang.RuntimeException: Unable to start activity ComponentInfo{todonotes.com.todonotes_buildfinale/todonotes.com.todonotes_buildfinale.ContactDetailActivity}: java.lang.NullPointerException: Attempt to invoke virtual method 'void android.app.ActionBar.setDisplayHomeAsUpEnabled(boolean)' on a null object reference
                                                                                             at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2378)
                                                                                             at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2440)
                                                                                             at android.app.ActivityThread.access$800(ActivityThread.java:162)
                                                                                             at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1348)
                                                                                             at android.os.Handler.dispatchMessage(Handler.java:102)
                                                                                             at android.os.Looper.loop(Looper.java:135)
                                                                                             at android.app.ActivityThread.main(ActivityThread.java:5422)
                                                                                             at java.lang.reflect.Method.invoke(Native Method)
                                                                                             at java.lang.reflect.Method.invoke(Method.java:372)
                                                                                             at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:914)
                                                                                             at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:707)
                                                                                          Caused by: java.lang.NullPointerException: Attempt to invoke virtual method 'void android.app.ActionBar.setDisplayHomeAsUpEnabled(boolean)' on a null object reference
                                                                                             at todonotes.com.todonotes_buildfinale.ContactDetailActivity.onCreate(ContactDetailActivity.java:59)
                                                                                             at android.app.Activity.performCreate(Activity.java:6057)
                                                                                             at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1106)
                                                                                             at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2331)
                                                                                             at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2440) 
                                                                                             at android.app.ActivityThread.access$800(ActivityThread.java:162) 
                                                                                             at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1348) 
                                                                                             at android.os.Handler.dispatchMessage(Handler.java:102) 
                                                                                             at android.os.Looper.loop(Looper.java:135) 
                                                                                             at android.app.ActivityThread.main(ActivityThread.java:5422) 
                                                                                             at java.lang.reflect.Method.invoke(Native Method) 
                                                                                             at java.lang.reflect.Method.invoke(Method.java:372) 
                                                                                             at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:914) 
                                                                                             at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:707) 


my manifest is:

<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="todonotes.com.todonotes_buildfinale">

    <uses-permission android:name="android.permission.INTERNET"/>
    <uses-permission android:name="android.permission.ACCESS_NETWORK_STATE"/>
    <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"/>
    <uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE"/>
    <uses-permission android:name="android.permission.READ_CONTACTS"/>

    <application
        android:allowBackup="true"
        android:icon="@mipmap/ic_launcher"
        android:label="@string/app_name"
        android:supportsRtl="true"
        android:theme="@style/Theme.AppCompat.NoActionBar">

        <activity android:name="todonotes.com.todonotes_buildfinale.SplashScreen"
            android:label="@string/app_name">
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />

                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>

        <activity android:name="todonotes.com.todonotes_buildfinale.LoginActivity" android:theme="@style/AppTheme.Dark"
            android:label="@string/app_name">
            <intent-filter>
                <action android:name="todonotes.com.todonotes_buildfinale.SIGNUPACTIVITY"/>

                <category android:name="android.intent.category.DEFAULT" />
            </intent-filter>
        </activity>


        <activity
            android:name="todonotes.com.todonotes_buildfinale.ContactsListActivity" android:theme="@style/AppTheme"
            android:label="@string/activity_contacts_list"
            android:windowSoftInputMode="adjustResize">

            <intent-filter>
                <action android:name="android.intent.action.MAIN" />
                <category android:name="android.intent.category.DEFAULT" />
            </intent-filter>
            <!-- Add intent-filter for search intent action and specify searchable configuration
                 via meta-data tag. This allows this activity to receive search intents via the
                 system hooks. In this sample this is only used on older OS versions (pre-Honeycomb)
                 via the activity search dialog. See the Search API guide for more information:
                 http://developer.android.com/guide/topics/search/search-dialog.html -->
            <intent-filter>
                <action android:name="android.intent.action.SEARCH" />
            </intent-filter>
            <meta-data android:name="android.app.searchable"
                android:resource="@xml/searchable_contacts" />
        </activity>
        <activity
            android:name="todonotes.com.todonotes_buildfinale.ContactDetailActivity"  android:theme="@style/AppTheme"
            android:label="@string/activity_contact_detail"
            android:parentActivityName="todonotes.com.todonotes_buildfinale.ContactDetailActivity">
            <!-- Define hierarchical parent of this activity, both via the system
                 parentActivityName attribute (added in API Level 16) and via meta-data annotation.
                 This allows use of the support library NavUtils class in a way that works over
                 all Android versions. See the "Tasks and Back Stack" guide for more information:
                 http://developer.android.com/guide/components/tasks-and-back-stack.html
            -->
            <meta-data android:name="android.support.PARENT_ACTIVITY"
                android:value="todonotes.com.todonotes_buildfinale.ContactDetailActivity" />
        </activity>
        <activity android:name="todonotes.com.todonotes_buildfinale.SignupActivity" android:theme="@style/AppTheme.Dark"></activity>
        <activity android:name="todonotes.com.todonotes_buildfinale.ConfirmActivity" android:theme="@style/AppTheme.Dark"></activity>
        <activity android:name="todonotes.com.todonotes_buildfinale.ListNoteActivity" android:theme="@style/AppTheme.Dark"></activity>

    </application>

</manifest>


how can i resolve this?? is urgent
 
