Do not move desktop task to the next display

This CL changes the move to next display shortcut (Ctrl + Action + D) so
that it does not move desktop tasks if the destination display has
focused non-desktop tasks (e.g. fullscreen, split screen)

Bug: 410637225
Test: DesktopTasksControllerTest
Test: run CD smoke tests https://android-build.corp.google.com/builds/abtd/run/L66200030013068147
Flag: com.android.window.flags.enable_move_to_next_display_shortcut
Change-Id: I3c723583bc76e0baabb05515132f67c40587b45e