QuickMessage: Fix the dialog size for the N4

On the N4, the keyboard seems to be taller and it overlaps the bottom
of the QuickMessage dialog.  This commit makes the pop-up 5dip shorter
so that it maintains a small gap between the dialog and the keyboard.

Change-Id: Idf80d2192d4ef6b0ba0abb1d48908e0d8b7216dc