Merge "Revert "Allow bar to be transparent if letterbox contains bar"" into rvc-dev am: 64682e76f2 am: fe5a7698e9

Original change: https://googleplex-android-review.googlesource.com/c/platform/frameworks/base/+/12128053

Change-Id: I7990c76124dc4c9b5577fad88b2ff5a252d2d8bd