Set the permissions of wifi supplicant file so that system can access it.

Create the required directories and set the correct owner and permissions.

rootdir/init.rc

@@ -78,6 +78,11 @@ loglevel 3
     mkdir /data/misc/keystore 0770 keystore keystore
     mkdir /data/misc/vpn 0770 system system
     mkdir /data/misc/vpn/profiles 0770 system system
+    mkdir /data/misc/wifi 0770 wifi system
+    chown wifi system /data/misc/wifi
+    touch /data/misc/wifi/wpa_supplicant.conf
+    chmod 0660 /data/misc/wifi/wpa_supplicant.conf
+    chown wifi system /data/misc/wifi/wpa_supplicant.conf
     mkdir /data/local 0771 shell shell
     mkdir /data/local/tmp 0771 shell shell
     mkdir /data/data 0771 system system