Themes: Fix home button for realz

AOSP doesn't update or refresh home button, its drawable is loaded once.
Refresh home button when refreshing recents and back icons aswell.

Change-Id: Ic691563bddcda00cff985edc2d0980172e81db0d
Signed-off-by: Evan Anderson <evan@thelinuxman.us>

Conflicts:
	packages/SystemUI/src/com/android/systemui/statusbar/phone/NavigationBarView.java
Change