Add required attributes

Author: rynowak

src/Microsoft.Extensions.Configuration.FileProviderExtensions/Properties/AssemblyInfo.cs

@@ -0,0 +1,9 @@
+// Copyright (c) .NET Foundation. All rights reserved.
+// Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.
+
+using System.Reflection;
+using System.Resources;
+using System.Runtime.CompilerServices;
+
+[assembly: AssemblyMetadata("Serviceable", "True")]
+[assembly: NeutralResourcesLanguage("en-US")]