Dialer: Add Dialpad key padding [1/3]

Add top and bottom padding to Dialpad number keys to make the layout seem
        less crowded.

Change-Id: Icff66900ec8c2bd01188cfdf34a6b56ea04542a3
Merge branch 'kk4.4' of https://github.com/SlimRoms/packages_apps_Dialer into kk4.4