Revert "Mark as experiemental"

This reverts commit 4275312e5174149357283c263e10c45c5552dd4b.

src/csharp/Grpc.Tools/build/_grpc/Grpc.CSharp.xml

@@ -28,7 +28,7 @@
 
     <EnumProperty Name="ClientBaseType" DisplayName="gRPC Client Base Type"
                   Category="gRPC" Default="ClientBase"
-                  Description="The base type to use for the client. This is an experimental feature.">
+                  Description="The base type to use for the client.">
       <EnumValue Name="ClientBase" DisplayName="Use ClientBase" />
       <EnumValue Name="LiteClientBase" DisplayName="Use LiteClientBase" />
       <EnumProperty.DataSource>