Merge "Fix race condition causing screenshot view to be added to window twice" into sc-qpr1-dev am: 4c76184ee1 am: 88bf3ce5f7 am: 053bfbfbc9

Original change: https://googleplex-android-review.googlesource.com/c/platform/frameworks/base/+/15717016

Change-Id: Ie2c761708ead79716a8eb832971e3c4d11843a75