Set media folder +F for adopted storage as well

We previously only set +F for /data/media, but adopted storage needs
this as well. Instead we add support for adding attrs to PrepareDir.

Bug: 163453310
Test: sm set-virtual-disk true
      follow UI setup and confirm +F on /mnt/expand/*/media
Change-Id: I08f13b57a4de3538e88b38eb95b0ac115a5a5ce8
Merged-In: I08f13b57a4de3538e88b38eb95b0ac115a5a5ce8
diff --git a/Utils.h b/Utils.h
index 04cbac4..5351450 100644
--- a/Utils.h
+++ b/Utils.h
@@ -67,7 +67,8 @@
                           bool fixupExisting);
 
 /* 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);
+status_t PrepareDir(const std::string& path, mode_t mode, uid_t uid, gid_t gid,
+                    unsigned int attrs = 0);
 
 /* Really unmounts the path, killing active processes along the way */
 status_t ForceUnmount(const std::string& path);