galaxys2-common: Update storage configuration for 4.4

See: http://source.android.com/devices/tech/storage/config-example.html

Credits to Steven Luo (steven676), Andrew Jiang (jiangyi), and
Hernan Castañon Álvarez for this.

Change-Id: I30644e476d971f694bf6a9a37f9b180d3b951c13