Allow dreams to redraw when device is rotated.

Dreams currently will close and recreate a Dream when the device
rotates. This causes a bug in the Dream state as the current activity
closes but the device does not exit a Dreaming state.

Bug: 235263108
Bug: 239510155
Test: atest DreamManagerServiceTests#testDreamNotFinishAfterRotation
Change-Id: I01d803fd501f71da016395ad24a1fe0f92200b26