Swap volume buttons when the screen is rotated by 90 or 180 degrees (1/2)

See: http://review.cyanogenmod.org/#/c/14530/

Change-Id: I201febc2827e6fbd347cb0e3f8d3347ad1bc487b

Conflicts:
	core/java/android/provider/Settings.java
	media/java/android/media/AudioManager.java