Merge "Force-clear nav bar flags when phone finishes booting." into rvc-dev am: b236787b am: eb688524 am: 8bce6286

Original change: https://googleplex-android-review.googlesource.com/c/platform/frameworks/base/+/11813213

Change-Id: I51f9cc76e275956a63ac076770d0472bb2f20d43