Ensures the destination display gains global focus

This change fulfills a UX requirement where pressing the "move to next
display" shortcut twice should move the same window.

When DesktopTasksController handles keyboard shortcuts, it moves the
task that has the global focus. This concept was recently introduced
with the display focus feature.

Previously, the display focus remained on the source display even after
a task was moved. This caused the next task on the source display to
gain global focus. This CL rectifies this by adding reorder requests to
the reparent transaction. This ensures the destination display moves to
the top and receives the display focus.

Bug: 381763302
Flag: com.android.window.flags.enable_move_to_next_display_shortcut
Flag: com.android.window.flags.enable_display_focus_in_shell_transitions
Test: DesktopTasksControllerTest
Change-Id: I4270b5a3dc60ab07604dd3b1c6b95f8f9c06ac04