Framework: Forward port Long press back to kill app

Original author: DaneshM

Change-Id: I54f4fb861897fe713cffa15422535c5091a0c095

Conflicts:

	core/res/res/values/symbols.xml
	policy/src/com/android/internal/policy/impl/PhoneWindowManager.java

	modified:   core/java/android/provider/Settings.java
	modified:   core/res/res/values/strings.xml
	modified:   core/res/res/values/symbols.xml
	modified:   policy/src/com/android/internal/policy/impl/PhoneWindowManager.java