Navigation Bar: Toggle last app on recents button long press

Change-Id: I1e6d6255494991b440f3cf5854a7edad7fee2c1b

Conflicts:
	packages/SystemUI/src/com/android/systemui/statusbar/BaseStatusBar.java
	packages/SystemUI/src/com/android/systemui/statusbar/phone/PhoneStatusBar.java
Fix last app toggle for Android 4.4
Needed to modify some of the code to get the feature building on KitKat.