Execute DelayedCallback outside CallbackScheduler lock

The execution will lock the VibratorService.mLock object to finish the
current vibratio, and the CallbackScheduler will require the same lock
to start a new vibration. This is currently causing a deadlock.

Fix: 166285780
Fix: 163901838
Test: atest CorePerfTests:ViewPerfTest
Change-Id: I9631166de3546154ce738c9688fadf3d0442e4d3