DO NOT MERGE: camera2: Fix race with stream deletion during disconnect.

Bug: 11856804

- Shutdown order in Camera2Client allows a stream to be
  deleted before the corresponding processing thread has
  quit.  This can result in updates being called on the
  processor thread without a valid stream.

Change-Id: Ie4e649771f4321498659211f2a37ed89a6d956c4
1 file changed