Forward Port: Volume button seek on screen off [2/2]

PS : Fix the short press event type

Change-Id: Id55a1240a133b5144502fced862bae040b390662
Signed-off-by: cj360 <ayunker551@gmail.com>

Conflicts:
	core/java/android/provider/Settings.java
	policy/src/com/android/internal/policy/impl/PhoneWindowManager.java