Ignore non-pointer events in LetterboxScrollProcessor

Non-pointer events don't correspond to any location on the screen, so they can't be used to scroll the letterbox.

Bug: 380510280
Change-Id: Ifb5cf30458595a94fb2969e0ba9b24d324fa1407
Flag: com.android.window.flags.scrolling_from_letterbox
Test: Manual
1 file changed