Apply static offset to PiP IME adjustment.

Bug: 63581892
Test: Enter PiP, launch an app with a bottom aligned input view and focus
      it. Ensure that the PiP is offset sufficiently to see the view.

Change-Id: Ice0d77b25b34d389f604f8154bdf7c866be668e5
(cherry picked from commit 136d1ec8)