[DnD] Reparent and change scale on move across displays

Keep track of the latest DisplayContent the surface moved
and keep the original to help animator decides the animation
later

Bug: 365512241
Test: atest WmTests:DragDropControllerTests
Flag: com.android.window.flags.enable_connected_displays_dnd
Change-Id: I2afe28aad1a25680ba30a8e551fcfb6640acb0aa