1. Replace use of java.util.HashMap with android.util.ArrayMap in

LauncherAppsCompatVL class.
2. Fix Synchronization on a non-final field 'mCallbacks'.
3. Add missing @Override to the overriden methods.
4. Add missing @NonNull to the method parameters.
Bug: 62466540

Change-Id: I0d650bfe5b7e390db7090c2ae29a8622d49073d7