Merge "Gracefully stop the GeneratorHub worker thread in destructor" into rvc-qpr-dev am: a216f7fade am: d8c5052cd1

Original change: https://googleplex-android-review.googlesource.com/c/platform/hardware/interfaces/+/13807297

MUST ONLY BE SUBMITTED BY AUTOMERGER

Change-Id: Ibc7c6f87ba19dda040bf15d2ce28276495b50993