Using the fixed version of package in 2 test asset projects

Author: Simon Zhao (BEYONDSOFT CONSULTING INC)

test/TestAssets/TestPackages/dotnet-new/test_templates/PostActions/RestoreNuGet/Files_MatchSpecifiedFiles/Tool.Test/Tool.Test.csproj

@@ -8,7 +8,7 @@
 	</PropertyGroup>
 
 	<ItemGroup>
-		<PackageReference Include="Microsoft.NET.Test.Sdk" Version="$(MicrosoftNETTestSdkPackageVersion)" />
+		<PackageReference Include="Microsoft.NET.Test.Sdk" Version="17.1.0" />
 		<PackageReference Include="xunit" Version="2.4.1" />
 		<PackageReference Include="xunit.runner.visualstudio" Version="2.4.3">
 			<IncludeAssets>runtime; build; native; contentfiles; analyzers; buildtransitive</IncludeAssets>

test/TestAssets/TestProjects/XUnitTestProject/XUnitTestProject.csproj

@@ -5,7 +5,7 @@
   </PropertyGroup>
 
   <ItemGroup>
-    <PackageReference Include="Microsoft.NET.Test.Sdk" Version="$(MicrosoftNETTestSdkPackageVersion)" />
+    <PackageReference Include="Microsoft.NET.Test.Sdk" Version="15.0.0" />
     <PackageReference Include="xunit" Version="2.2.0" />
     <PackageReference Include="xunit.runner.visualstudio" Version="2.2.0" />
   </ItemGroup>