experimental wifi changes

Change-Id: I1f64e0001d202f1e426179f483600298b4650b4d
use aosp wpa supplicant

Change-Id: Ibd50394cb3d2aa6cf5fe6de8ea376d005a13e6e3
props for 512mb devices

Change-Id: I4ae5ab9206af2e4f6ec02bcdffd2a3d4bf3fe79f
fix sdcard permissions

Change-Id: I724c387fc5294982e1ef04302518a5c069948a9c