Fix InformationalVersion in corelib generators

Author: akoeplinger

src/libraries/System.Private.CoreLib/gen/System.Private.CoreLib.Generators.csproj

@@ -2,6 +2,9 @@
   <PropertyGroup>
     <TargetFramework>netstandard2.0</TargetFramework>
     <NoWarn>$(NoWarn);CS3001</NoWarn>
+    <!-- Override InformationalVersion during servicing as it's returned via public api. -->
+    <InformationalVersion Condition="'$(PreReleaseVersionLabel)' == 'servicing'">$(ProductVersion)</InformationalVersion>
+    <InformationalVersion Condition="'$(StabilizePackageVersion)' == 'true'">$(ProductVersion)</InformationalVersion>
   </PropertyGroup>
 
   <ItemGroup>