Tie VR mode support to a property

Bug: 35854545
Test:
  - Validate VR mode is not supported when ro.boot.vr is unset
  - Validate VR mode is supported when ro.boot.vr is set

Change-Id: I26f7e851766eab0d8a5a2f9fb4d72bfcee0c42f3
2 files changed