Merge "Fix crash when trying to get bar transitions before nav bar is created"...

Merge "Fix crash when trying to get bar transitions before nav bar is created" into sc-dev am: 66072f6b am: dd1a34fb

Original change: https://googleplex-android-review.googlesource.com/c/platform/frameworks/base/+/13887848

Change-Id: I28636fe9ed606d75587573dd521485a27187c2da