Remove /sdcard hack for shell users.

Using a /storage/sdcard0 symlink and a tmpfs staging area was used
to enable "/sdcard" paths for both zygote processes and the shell
user, but it breaks on devices with both emulated and physical
external storage.

Specifically, vold can't mount a physical sdcard onto the primary
storage symlink, and zygote can't re-bind-mount when secondary
storage is remounted after dropping privileges.

Bug: 7094858, 7064600
Change-Id: Ic9821129f94c22d0c64e84d8ee9f55d505a78e5d
diff --git a/init.tuna.rc b/init.tuna.rc
index 98be753..a55d833 100755
--- a/init.tuna.rc
+++ b/init.tuna.rc
@@ -3,12 +3,12 @@
 on init
     # See storage config details at http://source.android.com/tech/storage/
     mkdir /mnt/shell/sdcard0 0700 shell shell
+    mkdir /storage/sdcard0 0000 root root
 
     export EXTERNAL_STORAGE /storage/sdcard0
     export MULTIUSER_EXTERNAL_STORAGE /mnt/shell/sdcard0
 
     # Support legacy paths
-    symlink /mnt/shell/sdcard0/0 /storage/sdcard0
     symlink /storage/sdcard0 /sdcard
     symlink /storage/sdcard0 /mnt/sdcard