Experimental: Tapping on the status bar sends a space key.

While any IME is showing, taps on the empty region in the
center of the status bar will inject a KEYCODE_SPACE (62)
KeyEvent. This gives a huge Fitts' Law boost to LatinIME's
spacebar, which is easy to miss when typing quickly.

This is sort of a hack; a better solution would be to
translate the tap vertically until it enters the IME's
window and then hand the motion event back to the IME
(thereby accommodating IMEs that have something other than a
spacebar in their bottom row).

Bug: 3114340
Change-Id: Iabbfb5ca0000101074932304bce44eb6f7dca85d