VibratorService: Death Notifications

-Remove jni references to Vibration object
When the Vibration is completed, unlinkToDeath should be called on
the binder to remove previously registered death notifications.
This in-turn removes the jni global references to Vibration objects

-Register Vibrations without pattern for a death notification

-Check whether the vibration thread is completed, before unlinking the binder

Change-Id: I328614cbd784378508e691ebcef619c456e41ec5
CRs-Fixed: 228653, 231294