Introduce DWAppCompatAspectRatioPolicy

Create a new app compat policy which contains desktop windowing specific
aspect ratio logic for the inital bounds calculation. Since we know a
lot of information about the final state of the application, we can make
some assumption compared to the existing `AppCompatAspectRatioPolicy`.
For example, we can assume the windowing mode will be freefrom, that we
are not in table top or book mode and that the camera activity is not
active. This also differs from the `AppCompatAspectRatioPolicy` through
the way we access display information. As the activity record is not
fully populated at the point the initial bounds for desktop windowing
are created, we must access the display information through the task
instead.

Flag: NONE(unused code)
Bug: 353457301
Test: atest WmTests:DesktopAppCompatAspectRatioPolicyTests
Change-Id: I297f7a17f54871c134336282e839f3c0ce0c5182