Materialize the launcher icon, sd card icon, and feature graphic

Guidelines from http://www.androidpolice.com/2014/10/08/googles-new-vision-for-launcher-icons-paper-lighting-and-how-to-get-your-icon-ready/

Drop shadow of:
 Offset 7: 8
Widening Radius: 1
Blur Radius: 5
Shadow Opacity: 76