Use source display for desktop mode cleanup

When moving a task to another display, the desktop mode cleanup was
incorrectly using the destination display ID. This change ensures that
the cleanup is performed on the source display where the task
originated.

Bug: 424748132
Test: DesktopTasksControllerTest
Flag: com.android.window.flags.move_to_next_display_shortcut_with_projected_mode
Change-Id: I85a5934aa5b0794369ddf18f0d661d4fcdb52635