Merge "Nest SystemUI alert dialogs in NestedScrollLayout" into tm-dev am: ea91f5bb91 am: fdf53ba01f

Original change: https://googleplex-android-review.googlesource.com/c/platform/frameworks/base/+/17756832

Change-Id: I2082ccee285314fc246a10cd07e77e3ce25f561d
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>