[Settings] HW keys tweaks

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

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

Change-Id: Ifa62211ef1e12613cc69dc19798bccfd81a0a3c1