Test ref pack fix

Author: John Luo

src/Framework/ref/Microsoft.AspNetCore.App.Ref.csproj

@@ -130,13 +130,13 @@ This package is an internal implementation of the .NET Core SDK and is not meant
       <!-- Exclude transitive external dependencies that are not directly referenced by projects in AspNetCore or Extensions -->
       <AspNetCoreReferenceAssemblyPath
           Include="@(ReferencePathWithRefAssemblies)"
+          Condition="'%(ReferencePathWithRefAssemblies.IsReferenceAssembly)' == 'true'"
           Exclude="
             @(_ReferencedExtensionsRefAssemblies);
             @(ReferencePathWithRefAssemblies->WithMetadataValue('NuGetPackageId', 'Microsoft.NETCore.App.Ref'));
             @(ReferencePathWithRefAssemblies->WithMetadataValue('NuGetPackageId', 'System.Security.Cryptography.Pkcs'));
             @(ReferencePathWithRefAssemblies->WithMetadataValue('NuGetPackageId', 'System.Drawing.Common'));
             @(ReferencePathWithRefAssemblies->WithMetadataValue('NuGetPackageId', 'Microsoft.Win32.SystemEvents'));
-            @(ReferencePathWithRefAssemblies->WithMetadataValue('IsReferenceAssembly', 'false'));
             @(ReferencePathWithRefAssemblies->WithMetadataValue('ReferenceGrouping', 'Microsoft.NETCore.App'));" />
 
       <AspNetCoreReferenceAssemblyPath