Only rotate seamlessly if the app window fills its parent

e.g. An activity with fixed aspect ratio:
----------
|        |    -----------------
|        |    || |          | |
|Activity| -> || | Activity | |
|        |    || |          | |
|________|    || |          | |
|  Lbox  |    -----------------
==========   <^              ^ Letterbox
              Navigation bar

The relative position is changed after rotation, so it may
look like a sudden jump when rotating seamlessly.

Bug: 112288258
Test: atest DisplayPolicyTests#testShouldRotateSeamlessly
Change-Id: I520534e11b35e3d570bc7f65198bc3cc3c82aac1