Camera: Improve docs for session parameters am: 622e3bd686 am: e9907fc80a am: 06100c93c7 am: 0198df0d8d

Original change: https://googleplex-android-review.googlesource.com/c/platform/frameworks/av/+/24621696

Change-Id: I935b65ba8bd296b94fdbc550841ebbc244c3647d
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>