Add icon for MultiDisplayDragMoveIndicatorSurface

MultiDisplayDragMoveIndicatorSurface is the surface rendered on the new
display to indicator the window position during window drag across
displays. Currently, it's an empty rect surface. This commit adds a icon
in the middle for it.

Bug: 409218149
Test: atest MultiDisplayDragMoveIndicatorSurfaceTest
Flag: com.android.window.flags.enable_connected_displays_window_drag
Change-Id: Ib5a7e61d912225a4546c07e9ea73a073efd9499c