Merge "Camera: Exit PreviewStreamSpacer when disconnecting stream" into tm-dev am: c3a3ee83 am: 16f61fcb am: 62d0623c

Original change: https://googleplex-android-review.googlesource.com/c/platform/frameworks/av/+/18415584



Change-Id: I3927417bf684275589b6fba8e28d4717a7968086
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>