Merge "Revert^2 "Introduce Windowless starting window."" into udc-dev am: 0b2aa295

Original change: https://googleplex-android-review.googlesource.com/c/platform/frameworks/base/+/21794181



Change-Id: I7e9423a82695b3239c01d7bc7fa7d874635affbc
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>