Merge "Postpone window_state_changed events until the window is added" into tm-dev am: 857459ff am: 6fbe6cb2

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



Change-Id: I6ab729fd31fdc1fef2dfbd7f36a059538964f1a7
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>