Add onPointerDownOutsideFocus for events outside the focused window (2/4)

Post the onPointerDownOutsideFocus command when the conditions are satisfied.
Added onPointerDownOutsideFocus to the InputDispatcherPolicyInterface so the
callback can be sent to the client.

Bug: 122535136
Test: InputDispatcherOnPointerDownOutsideFocus
Change-Id: Ifec75daf1fff4ef83e0c230829400abb5a065d7f