Merge "Get starting window background color directly." into sc-dev am: a9a86113 am: 992684e1 am: e7474b0d

Original change: https://googleplex-android-review.googlesource.com/c/platform/frameworks/base/+/15020163

Change-Id: Iba24c68fe5d451b613d4e1ddad108a480f7b29e0