Merge "Postpone window_state_changed events until the window is added" into...

Merge "Postpone window_state_changed events until the window is added" into tm-dev am: 857459ff am: 4db5aded am: 70baefda am: 636ecf6b

Original change: https://googleplex-android-review.googlesource.com/c/platform/frameworks/base/+/17741153



Change-Id: I7590bd8a9f2eae72edd420c81da3ed312a189e4d
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>