Active Display: Small cleanup

Change-Id: I61298a6a5b848159d9cb5746b54384c1ec06fe9b
Active display: Allow apps to be excluded from being displayed [1/2]

This has been a highly requested feature so I guess it's about time
we implement it :).

Change-Id: I5c334833b78325733ae076c07afccebb02758ead

Conflicts:
	core/java/android/provider/Settings.java