Revert nuget.config change

Author: JoeRobich

NuGet.Config

@@ -2,13 +2,13 @@
 <configuration>
     <packageSources>
         <clear />
-        <add key="dotnet-public" value="https://pkgs.dev.azure.com/dnceng/public/_packaging/dotnet-public/nuget/v3/index.json" />
+        <add key="NuGet" value="https://api.nuget.org/v3/index.json" />
         <add key="dotnet-tools" value="https://pkgs.dev.azure.com/dnceng/public/_packaging/dotnet-tools/nuget/v3/index.json" />
         <add key="dotnet6" value="https://pkgs.dev.azure.com/dnceng/public/_packaging/dotnet6/nuget/v3/index.json" />
     </packageSources>
     <packageSourceMapping>
         <clear />
-        <packageSource key="dotnet-public">
+        <packageSource key="NuGet">
             <package pattern="Antlr4.*" />
             <package pattern="BenchmarkDotNet" />
             <package pattern="BenchmarkDotNet.*" />