Merge pull request #13510 from dotnet/joeloff/8xxSignSHA2

Update authenticode to use SHA2

Author: joeloff

build/Signing.proj

@@ -6,7 +6,7 @@
          property here to avoid importing files we don't need for signing which would cause errors if imported when using MSBuild 14. -->
     <BuildingSigningProject>true</BuildingSigningProject>
     <ExternalCertificateId Condition="'$(ExternalCertificateId)' == ''">135020002</ExternalCertificateId>
-    <InternalCertificateId Condition="'$(InternalCertificateId)' == ''">Microsoft402</InternalCertificateId>
+    <InternalCertificateId Condition="'$(InternalCertificateId)' == ''">Microsoft400</InternalCertificateId>
     <NugetCertificateId Condition="'$(NugetCertificateId)' == ''">NuGet</NugetCertificateId>
   </PropertyGroup>