Merge "Add comments stating the configs for visible background users are not ready for production" into udc-dev am: 5191e0d7 am: 208bd182 am: d27bd256 am: abb45d18

Original change: https://googleplex-android-review.googlesource.com/c/platform/frameworks/base/+/24140525



Change-Id: Ibf8bdb7dbc0972d6bbf0491878464c25e067430b
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>