Merge "Add unregisterClient in instance close." into sc-dev am: f03fa75c am: 97d5975d am: 8a783a2a

Original change: https://googleplex-android-review.googlesource.com/c/platform/frameworks/base/+/15238310

Change-Id: I418b170eb6a3a3c6e27eb4c2d319f4c3c32d953e