Merge "Transitions - Listen for bouncer show & hide" into tm-qpr-dev am: be5367c9 am: c54aaa16

Original change: https://googleplex-android-review.googlesource.com/c/platform/frameworks/base/+/20639790



Change-Id: If4488f8280e4a810dd45963c848248f195ff6686
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>