Merge "[a11y] When multi-user switcher is selected in lockscreen and Talkback...

Merge "[a11y] When multi-user switcher is selected in lockscreen and Talkback is enabled, play helpful explanation." into tm-qpr-dev am: 168133e3

Original change: https://googleplex-android-review.googlesource.com/c/platform/frameworks/base/+/19135806



Change-Id: I4bdd5758009fdd833ff05be8f3bed9006605bbde
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>