IME support for trackball and generic motion events

Trackball and generic motion events now pass through the IME in case
it would like to handle them before passing them on to the view
hierarchy.

While I was at it, I also...
...fixed the documentation on InputMethodService.onKeyUp()
...added documentation to InputMethodService.onTrackballEvent()
...added trackball and generic motion events to the "input" command
...fixed input consistency verification involving ACTION_OUTSIDE

Bug: 7050005
Change-Id: I40ab68df4a9542af6df25de6ec2ec500e4c02902