Reset "allowAllRotations" when the physical display changed.

Previously the config resource was read once and cached forever.

There are different config resource values based on the screen
dimensions, therefore we need to make sure that the value is reset
when displays change.

Test: DisplayRotationTests, DisplayWindowSettingsTest +
      Manually on device
Bug: 203814571
Change-Id: I116d9922342ea4f1ca5858873a1d38c4c5d52161