Revert "FW: Remove Hover [2/2]"

This reverts commit 41e9b3f743f84b5e766e592d8c255fdf9bbb86fa.

Conflicts:
	core/java/android/app/INotificationManager.aidl
	packages/SystemUI/res/layout/status_bar_expanded_header.xml
	packages/SystemUI/src/com/android/systemui/ExpandHelper.java
	packages/SystemUI/src/com/android/systemui/statusbar/BaseStatusBar.java
	packages/SystemUI/src/com/android/systemui/statusbar/phone/PhoneStatusBar.java
	services/input/InputWindow.cpp
	services/java/com/android/server/NotificationManagerService.java