Updates for expanded storage.

Mount private volumes at /mnt/expand, which is where we have new
SELinux policy waiting for us.  Also ensure that foundational
directories are ready when mounting.

Create local fs_prepare_dir() wrapper that sets SELinux context
based on path, avoiding the need for a later restorecon.

Use UUID as directory name for public volumes.  Wait a few seconds
before issuing first signal when force unmounting.

Bug: 19993667
Change-Id: If22595380faaae321705b06c87d877419620da48
diff --git a/Utils.h b/Utils.h
index 9e366e6..a6e1747 100644
--- a/Utils.h
+++ b/Utils.h
@@ -43,6 +43,9 @@
 status_t CreateDeviceNode(const std::string& path, dev_t dev);
 status_t DestroyDeviceNode(const std::string& path);
 
+/* fs_prepare_dir wrapper that creates with SELinux context */
+status_t PrepareDir(const std::string& path, mode_t mode, uid_t uid, gid_t gid);
+
 /* Really unmounts the path, killing active processes along the way */
 status_t ForceUnmount(const std::string& path);