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

Conflicts:
	src/com/android/dialer/dialpad/DialpadFragment.java
Merge branch 'cm-11.0' of https://github.com/temasek/android_packages_apps_Dialer into HEAD