Fix NullPointerException in RotationHelper

A possible race condition between RotationHelper and DisplayController is causing RotationHelper.onDisplayInfoChanged to be called after it has already been destroyed. Added checks to make Rotationhelper a no-op after being destroyed.

Flag: not needed
Fixes: 303506682
Test: AllAppsImageTest
Change-Id: Ief1946a356698eda9c2b806f9d49e08b1d66dae1
1 file changed