Use isDeviceEligibleForDesktopMode in tests

Instead of isDesktopModeSupported as there are other ways to be
elligible for desktop mode now.

Bug: 393404767
Bug: 382238347
Test: atest DesktopModeWindowDecorViewModelAppHandleOnlyTest
Test: atest DesktopModeWindowDecorViewModelTests
Test: atest DesktopActivityOrientationChangeHandlerTest
Test: atest DesktopModeKeyGestureHandlerTest
Test: atest DesktopTasksControllerTest
Test: atest DesktopModeStatusTest
Test: atest DesktopModeWindowDecorViewModelAppHandleOnlyTest
Test: atest DesktopModeLaunchParamsModifierTests
Flag: EXEMPT (fix test)
Change-Id: I4b219f9fbd24b8fc52e5ed27e3d5a4009d1a8415