HALO notification should open in floating window mode
If HALO is activated all HALO notifications will open in floating window mode. If HALO is not activated notifications will open in mutiwimdow mode.
mutliwindow: notify split view if layout changed

Change-Id: I793b6d3dd05a5d1bbea178e646a1c6f14dec35c3

Conflicts:
	services/java/com/android/server/am/ActivityManagerService.java
mutliwindow: notify split view if layout changed [2/2]

Change-Id: I2bbdd58dcf89cd70aa01a4c2bfc06641508f632c
multiwindow: Fix NullPointerException

Change-Id: I5c423bcde7d191331be53ce180f827e7023dc472