Merge "Add listeners for the creation and destruction of virtual displays. This will be used later by VibrationSettings to keep record of active virtual displays." into tm-qpr-dev am: 81b40baea8

Original change: https://googleplex-android-review.googlesource.com/c/platform/frameworks/base/+/19477752

Change-Id: I66fa50d09760d2308315ea27f35b37812d07ec02
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>