Remove hard-coded type in shared converter

Author: carolynvs

src/corelib/Compute/v2_1/Serialization/ServerCreateDefinitionConverter.cs

@@ -22,11 +22,11 @@ public override void WriteJson(JsonWriter writer, object value, JsonSerializer s
             base.WriteJson(writer, value, serializer);
 
             // Serialize scheduler hints
-            var server = value as ServerCreateDefinition;
+            dynamic server = value; // Using dynamic so that other vendors can use this converter as well
             if (server?.SchedulerHints != null)
             {
                 writer.WritePropertyName("os:scheduler_hints");
-                base.WriteJson(writer, server.SchedulerHints, serializer);
+                base.WriteJson(writer, (object)server.SchedulerHints, serializer);
             }
 
             writer.WriteEndObject();