Merge "Merge "vibrator: Document the source of always-on source IDs." into rvc-dev am: d3eb82f2a2 am: 830db903c2" into rvc-d1-dev-plus-aosp am: 932403ef70 am: 59832bd280

Change-Id: I62989621f4adf422de9d4e02bc131c92fda1c15c