Replace EnsureDirExists with a call to setupAppDir

Test: Manually verified ownership of /storage/emulated/0/Android/data on cf_x86_phone-userdebug after enabling feature
Bug: 151455752

Change-Id: I75a1e3b769476e56094e41d82e7f8e1a72827ded
diff --git a/VolumeManager.h b/VolumeManager.h
index b83871e..a9087fd 100644
--- a/VolumeManager.h
+++ b/VolumeManager.h
@@ -130,6 +130,8 @@
     int updateVirtualDisk();
     int setDebug(bool enable);
 
+    bool forkAndRemountStorage(int uid, int pid, const std::vector<std::string>& packageNames);
+
     static VolumeManager* Instance();
 
     /*