Merge "[flexiglass] Dismiss keyguard when any scene goes to Gone." into udc-qpr-dev am: 673448f9

Original change: https://googleplex-android-review.googlesource.com/c/platform/frameworks/base/+/24360121



Change-Id: Ib19b955861969bb4524c05ccfa2ded8693385bad
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>