Merge "[sysui] Use weak reference for the listener in...

Merge "[sysui] Use weak reference for the listener in NavigationBarTransitions" into tm-qpr-dev am: 5af264c1 am: 95881937

Original change: https://googleplex-android-review.googlesource.com/c/platform/frameworks/base/+/21931839



Change-Id: Ie291e25caf2d14445b5a744c0f016c21955266c6
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>