Camera: Improve docs for session parameters am: 622e3bd6 am: e9907fc8 am: 06100c93

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



Change-Id: I17efe180d93740de1b51959c8c0d70ef42c8a3d3
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>