Add transition handler for desktop disconnect.

In rare situations, the disconnect transition being animated by DefaultTransitionHandler resulted in crashes, causing CTS tests to fail on actviating the disconnect flag. This CL adds a transition handler that just applies the transactions to avoid them being animated by the default handler.

Additionally, this CL tweaks disconnect behavior to remove a desk if it is empty instead of moving it to a desktop-supported display.

Bug: 391652399
Test: Manual, atest
Flag: com.android.window.flags.enable_display_disconnect_interaction
Change-Id: Iaeeaa8cf28e57e6c5a65b8fe6f92abaa8db3427e