Merge "Revert "Allow bar to be transparent if letterbox contains bar"" into rvc-dev am: 64682e76f2 am: 6ddc9881ae

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

Change-Id: I8a3765defef2007553f09bc6ac3b806231ee7c8f