UITest: ref csproj indead of vcxproj

Author: Rosuavio

UITests/UITests.App/UITests.App.csproj

@@ -196,7 +196,7 @@
       <Project>{e7697922-9555-4cfb-aee0-c5f4d657e559}</Project>
       <Name>Microsoft.Toolkit.Uwp.DeveloperTools</Name>
     </ProjectReference>
-    <ProjectReference Include="..\..\Microsoft.Toolkit.UWP.Input.GazeInteraction\Microsoft.Toolkit.Uwp.Input.GazeInteraction.vcxproj">
+    <ProjectReference Include="..\..\Microsoft.Toolkit.UWP.Input.GazeInteraction\Microsoft.Toolkit.Uwp.Input.GazeInteraction.csproj">
       <Project>{a5e98964-45b1-442d-a07a-298a3221d81e}</Project>
       <Name>Microsoft.Toolkit.Uwp.Input.GazeInteraction</Name>
     </ProjectReference>