[1/n] Don't apply aspect ratio restrictions for resizeable activities in desktop mode

If a resizeable activity is in desktop mode, ignore all aspect ratio
constraints. Aspect ratio restrictions will still be applied on entry
into desktop mode.

Flag: com.android.window.flags.ignore_aspect_ratio_restrictions_for_resizeable_freeform_activities
Test: Manual - apply 16/9 user aspect ratio to resizeable application
and enter desktop mode. Resizing application should not cause letterbox.
Fixes: 381866902

Change-Id: I4c34111aae8180abb7f555a0395a32092e5feb32