Merge "Add migration indication area feature flag" into udc-dev am: fe5a1dc8c4 am: 0da8b900cb

Original change: https://googleplex-android-review.googlesource.com/c/platform/frameworks/base/+/23134078

Change-Id: I109d2ef4d17f1b3247fd9eaa2de1cb0b146b0fcd
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>