Reland "Revert "rootdir / sdcard : Stop creating /data/media/obb.""

This reverts commit 997a2d93d7a9216c248be9c983adec2d91283f5a.

Reason for revert: This revert is needed, just also need some selinux rules for changes to the script that runs if this folder is present.

Bug: 136199978
Change-Id: Ie0544954965e3c90abc2f833c41949976c3bea65
diff --git a/rootdir/init.rc b/rootdir/init.rc
index 2601997..1b7367c 100644
--- a/rootdir/init.rc
+++ b/rootdir/init.rc
@@ -586,6 +586,7 @@
     symlink /data/data /data/user/0
 
     mkdir /data/media 0770 media_rw media_rw
+    mkdir /data/media/obb 0770 media_rw media_rw
 
     mkdir /data/cache 0770 system cache
     mkdir /data/cache/recovery 0770 system cache