Allow some apps to get full access to external storage.

Apps with WRITE_MEDIA_STORAGE permission will get
full access to external storage.

Bug: 111890351
Test: manual

Change-Id: Icbfe1f68c0bfca77bdc557e9903ded45994f5945
diff --git a/core/java/com/android/internal/os/Zygote.java b/core/java/com/android/internal/os/Zygote.java
index 413f89d..927322e 100644
--- a/core/java/com/android/internal/os/Zygote.java
+++ b/core/java/com/android/internal/os/Zygote.java
@@ -81,6 +81,8 @@
     public static final int MOUNT_EXTERNAL_READ = IVold.REMOUNT_MODE_READ;
     /** Read-write external storage should be mounted. */
     public static final int MOUNT_EXTERNAL_WRITE = IVold.REMOUNT_MODE_WRITE;
+    /** Read-write external storage should be mounted instead of package sandbox */
+    public static final int MOUNT_EXTERNAL_FULL = IVold.REMOUNT_MODE_FULL;
 
     private static final ZygoteHooks VM_HOOKS = new ZygoteHooks();