Fix wallpaper window multi-touch

If the touched window has a wallpaper, then the touch event will be
duplicated to the wallpaper window when the foreground window received
a touch event.

When the foreground supports split touch, the wallpaper should deliver
the same events of foreground window.

And when the foreground window is transferred (caused by slippery or
transfer touch) to the new touched window, it has to check if the
wallpaper window should deliver the cancel event or keep in current
touch state.

Bug: 240308355
Test: atest inputflinger_tests
Change-Id: Ie53279f18838c459e528b24709aebf739290dc41