Forward port 'Swap volume buttons' (3/3)

Change-Id: I44a2b37b95848fff24c53c4c3561a3c000c487a1

Conflicts:

	res/values/cm_strings.xml
	res/xml/button_settings.xml
	src/com/android/settings/cyanogenmod/ButtonSettings.java

Conflicts:
	res/values/cm_strings.xml
	res/xml/button_settings.xml
	src/com/android/settings/ButtonSettings.java