Merge "Add null checks to browser callbacks" into rvc-dev am: 31a89937 am:...

Merge "Add null checks to browser callbacks" into rvc-dev am: 31a89937 am: 80333767 am: d65412f3 am: 0e754a1c

Original change: https://googleplex-android-review.googlesource.com/c/platform/frameworks/base/+/12035628

Change-Id: Ic6a4a9a94d02fa87877768c660ca1d7a52c098da