Merge "Camera: Improve documentation for 3A regions" into tm-dev am: 98dbbf702f am: 6d75e67576

Original change: https://googleplex-android-review.googlesource.com/c/platform/system/media/+/17453434

Change-Id: Ib0cc4485e224ef6d9a62f1fa3757b6339896d5b2
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>