Lockscreen Notifications: remove service intent from keyguard manifest

com.android.keyguard.NotificationListenerWrapper does not exist and this service intent adds lockscreen to Settings/Security/Notification access which will result in an endless and unrecoverable fc loop when selected

Change-Id: I8c76661508ac4e8fbc0b3b25002650b128b72e67
check mPressOnBackBehavior for null before injecting KeyEvent.KEYCODE_BACK

Change-Id: I24d0d77657e167a5ece7a78e503bfab1bf86849c