Base: use another Method to Kill app (NavRing Target)

sometimes SystemUi got Killed if enable NavRing Kill app
or using long press back button

this code fix that

taken from SlimRoms
https://github.com/SlimRoms/frameworks_base/commit/bbbb6f6fb2b1db59825b6a32ae136c72cac52bfa

Change-Id: If60b04105e77977df42ef32a91aeb7e5ea393531
Merge "Base: use another Method to Kill app (NavRing Target)" into android-4.4