[2/N] Interrupt DragToDesktop before bookend request -> move to Home

If the drag-to-desktop transition is interrupted before a cancel or end
transition has been requested:
- return to the Home screen
- cancel the current app handle drag

Test: launch a half-transparent activity while dragging a window to
desktop
Bug: 397135730
Bug: 397497184
Flag: com.android.window.flags.enable_drag_to_desktop_incoming_transitions_bugfix

Change-Id: Id0ea7f57fc1992faf66d096ceadea991bfec74e6