Merge "Fix race condition causing screenshot view to be added to window twice"...

Merge "Fix race condition causing screenshot view to be added to window twice" into sc-qpr1-dev am: 4c76184e am: 25e07c05 am: 022d9f15

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

Change-Id: If5b8515977cc97e75af1057961d49f1918eec2a7