Update drag resize input listener in bg thread

Creating and updating the listener requires multiple blocking binder
calls to grant / update input channels, which adds latency to the
decor's #relayout (and thus the shell transition as a whole).
To reduce latency, this change moves such calls to a background thread.

Bug: 396445663
Flag: com.android.window.flags.enable_drag_resize_set_up_in_bg_thread
Test: atest DragResizeInputListenerTest
Test: verify in perfetto binder calls are made in bg thread
Change-Id: I0474d6fe11afa057d52e04d1b624641f653b1dd1