Copy FocusEventDebugView MotionEvent before it gets recycled

The MotionEvent used to be copied in the "post" runnable, which runs
async from the calling thread which might have recycled the MotionEvent
before it gets copied. This fixes avoids that by doing the copy in the
same/caller runnable to ensure that there is no copy attempt of a
MotionEvent that has been recycled.

Bug: 339426797
Test: n/a
Change-Id: I9f7e33a84ee2debf93b58a6ee69fd1aef963ffe5