Merge "[Shell Transition]Fix occluded activity could show behind keyguard."...

Merge "[Shell Transition]Fix occluded activity could show behind keyguard." into tm-qpr-dev am: c050b87f am: 7689adc4

Original change: https://googleplex-android-review.googlesource.com/c/platform/frameworks/base/+/19656380



Change-Id: Idb88091ac285deb5fbe478385e18439b63e9e591
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>