added file header to new tests file

test/FunctionsV2/AzureStorageOptionsTests.cs

@@ -1,4 +1,7 @@
-using System;
+// Copyright (c) .NET Foundation. All rights reserved.
+// Licensed under the MIT License. See LICENSE in the project root for license information.
+
+using System;
 using System.Collections.Generic;
 using System.Linq;
 using System.Text;