Uncommit unnecessary file and remove buildprops template fluff

src/SourceBuild/content/test/Directory.Build.props

@@ -1,7 +1,2 @@
 <Project>
-  <!-- See https://aka.ms/dotnet/msbuild/customize for more details on customizing your build -->
-  <PropertyGroup>
-
-
-  </PropertyGroup>
 </Project>

src/SourceBuild/content/test/Microsoft.DotNet.UnifiedBuild.Tests/SdkKind.cs

@@ -1,14 +0,0 @@
-using System;
-using System.Collections.Generic;
-using System.Linq;
-using System.Text;
-using System.Threading.Tasks;
-
-namespace Microsoft.DotNet.UnifiedBuild.Tests
-{
-    internal enum SdkKind
-    {
-        Microsoft,
-        UnifiedBuild
-    }
-}