Show app handle based on screen size rather than activity's

Otherwise there would be no app handle on split screen

Fix: 392084559
Test: app handle shows on split screen on foldable
Test: DesktopModeWindowDecorViewModelAppHandleOnlyTest
Flag: EXEMPT this was the intended behavior
Change-Id: I7971fe1ba4215817ef106d48fd6e7d1d4af48798