Do not kill app when closing floating window

PS2: keep app when opening floating window from recents/slimrecents
PS3: remove blacklist stuff, since it's unsupported on DU
PS4: remove unused String
PS5: missed one flag

Change-Id: I151a475cd81354153951549a6f752b771f04be30

Conflicts:
	packages/SystemUI/src/com/android/systemui/oserecent/RecentPanelView.java
	packages/SystemUI/src/com/android/systemui/recent/RecentsPanelView.java