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
(cherry picked from commit 35708b9d7bcae0f9183de2848d782b2d0c54bcb6)
diff --git a/rootdir/init.rc b/rootdir/init.rc
index c042c48..893998c 100644
--- a/rootdir/init.rc
+++ b/rootdir/init.rc
@@ -589,6 +589,7 @@
     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
diff --git a/sdcard/sdcard.cpp b/sdcard/sdcard.cpp
index 0acea72..2b358197 100644
--- a/sdcard/sdcard.cpp
+++ b/sdcard/sdcard.cpp
@@ -214,14 +214,7 @@
 
     if (multi_user) {
         std::string obb_path = source_path + "/obb";
-        // Only attempt to prepare the /obb dir if it already exists. We want
-        // the legacy obb path "/data/media/obb" to be fixed up so that we can
-        // migrate it to its new location, but we don't want the directory to be
-        // created if it doesn't already exist.
-        struct stat sb;
-        if (TEMP_FAILURE_RETRY(lstat(obb_path.c_str(), &sb)) == 0) {
-            fs_prepare_dir(obb_path.c_str(), 0775, uid, gid);
-        }
+        fs_prepare_dir(obb_path.c_str(), 0775, uid, gid);
     }
 
     exit(0);