Merge "Update a11y label for unlock icon on lock screen." into tm-qpr-dev am: 2d8ced93

Original change: https://googleplex-android-review.googlesource.com/c/platform/frameworks/base/+/20424645



Change-Id: I7b62b75b637ec0504c720b880c07e6f9ba4a63f0
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>