Merge "Call preserveSurfaces when detaching children." into rvc-dev am: 5b72ddd8 am: 747665d4 am: 7a2e4522

Original change: https://googleplex-android-review.googlesource.com/c/platform/frameworks/base/+/11712621

Change-Id: I45e2008ad9dd4c3b5ba8ab506e725958c63ae9b9