Merge "Prevent lock icon a11y when unlocking." into udc-dev am: b3b3c283

Original change: https://googleplex-android-review.googlesource.com/c/platform/frameworks/base/+/23877262



Change-Id: Id02f650f5514a17042bf6a77b2bcd1787128ecc2
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>