Update codegen (#566)

Author: sfod

sdk/greengrass/greengrass-client/src/event-stream-rpc-java/model/software/amazon/awssdk/aws/greengrass/model/MessageContext.java

@@ -15,6 +15,9 @@
 import java.util.Optional;
 import software.amazon.awssdk.eventstreamrpc.model.EventStreamJsonMessage;
 
+/**
+ * The context is ignored if used in PublishMessage.
+ */
 public class MessageContext implements EventStreamJsonMessage {
   public static final String APPLICATION_MODEL_TYPE = "aws.greengrass#MessageContext";