Update build config

Author: SteveSandersonMS

eng/SharedFramework.External.props

@@ -51,7 +51,6 @@
     <ExternalAspNetCoreAppReference Include="Microsoft.JSInterop"                                          Version="$(MicrosoftJSInteropPackageVersion)" />
 
     <!-- Dependencies from dotnet/corefx -->
-    <ExternalAspNetCoreAppReference Include="System.ComponentModel.Annotations"                            Version="$(SystemComponentModelAnnotationsPackageVersion)" />
     <ExternalAspNetCoreAppReference Include="System.IO.Pipelines"                                          Version="$(SystemIOPipelinesPackageVersion)" />
     <ExternalAspNetCoreAppReference Include="System.Runtime.CompilerServices.Unsafe"                       Version="$(SystemRuntimeCompilerServicesUnsafePackageVersion)" />
     <ExternalAspNetCoreAppReference Include="System.Security.Cryptography.Xml"                             Version="$(SystemSecurityCryptographyXmlPackageVersion)" />
@@ -91,6 +90,7 @@
   -->
   <ItemGroup Condition="'$(TargetFramework)' == 'netstandard2.0'">
     <_CompilationOnlyReference Include="System.Buffers" />
+    <_CompilationOnlyReference Include="System.ComponentModel.Annotations" />
   </ItemGroup>
 
   <!--