Set up configfs

Bug: 19160983
Change-Id: I8fddf11fb6124950dfa2528a4f420abd9d461df6
Signed-off-by: Daniel Rosenberg <drosen@google.com>

rootdir/init.rc

@@ -62,6 +62,10 @@ on init
     mount tmpfs tmpfs /mnt mode=0755,uid=0,gid=1000
     restorecon_recursive /mnt
 
+    mount configfs none /config
+    chmod 0775 /config/sdcardfs
+    chown system package_info /config/sdcardfs
+
     mkdir /mnt/secure 0700 root root
     mkdir /mnt/secure/asec 0700 root root
     mkdir /mnt/asec 0755 root system