HALO: keep apps in recents

Change-Id: I9ede8a1aba8d6721f077a39a31b6cc5cd8272dc2

Conflicts:
	services/java/com/android/server/am/ActivityRecord.java

Conflicts:
	core/java/android/app/Activity.java
	core/java/android/app/LayerActivity.java
	packages/SystemUI/src/com/android/systemui/recent/RecentsPanelView.java
	services/java/com/android/server/am/ActivityRecord.java