Merge "Only draw legacy nav bar background when it is visible" into...

Merge "Only draw legacy nav bar background when it is visible" into udc-qpr-dev am: e4ef060e am: e41472bd

Original change: https://googleplex-android-review.googlesource.com/c/platform/frameworks/base/+/24735364



Change-Id: I68e377b317d03511dae34bf2449d59ad38392c5d
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>