Settings: Forward port Kill app back long press

Original author: DaneshM

Change-Id: Ide8be24d679d0b3d74bf56b33696dc279de49470

Conflicts:
	res/values/strings.xml
	res/xml/development_prefs.xml
	src/com/android/settings/DevelopmentSettings.java

Conflicts:
	res/values/strings.xml