docs: Clarified definition of KeyEvent.Callback.onKeyMultiple()

The onKeyMultiple() event captures simulated, not actual, presses of
the same key in rapid succession. Adjusted the method definition to
include this clarification.

Bug: 2335983
Change-Id: Id01182d81dafe98df9e559ff24f9e1d5a1f949c3
1 file changed