base: fix external sdcard mountpoint

It needs to add that line on init.xxxx.rc on rootdir folders.

"chown root root /mnt/media_rw"

Needed for devices that has some troubles mounting storages.

Credits: http://forum.xda-developers.com/showthread.php?t=2537793
SystemUI: add CHANGE_NETWORK_MODE permission

Required for 2G/3G quick settings toggle

Change-Id: I72392bd995d12c22388c99f34abb431cd0be8f0d