Update local value of sensorBounds whenever it changes

Fixes: 283404990
Test: verified manually,
  1. enroll UDFPS, enable auto-rotate.
  2. Lock the device
  3. Trigger secure camera
  4. Open locked gallery to trigger UDFPS overlay in portrait orientation
  5. Rotate phone to landscape orientation
  6. Camera app rotates in the background
  7. UDFPS icon should be visible after the rotation and show up in correct position
Change-Id: Iae7f419622dd1c06937b5420255a935eef555891