Fix bug #12957228 Java crash in com.android.settings: java.lang.IllegalStateException:

...Can not perform this action after onSaveInstanceState

- prevent a click on the Drawer's Headers when the App is paused / finished
- register / unregister the DrawerListener when needed

Change-Id: Ia270ef27b23c66d55565bbb73d4f6a6531b742d2