Avoid duplicate registration of [RequestBody|ResponseBody]Advice @ControllerAdvice

Prior to this commit, if a @ControllerAdvice implemented both
RequestBodyAdvice and ResponseBodyAdvice, it was registered twice in
RequestMappingHandlerAdapter.

This commit ensures that such instances are only registered once.

Closes gh-22638

spring-webmvc/src/main/java/org/springframework/web/servlet/mvc/method/annotation/RequestMappingHandlerAdapter.java

 /*
- * Copyright 2002-2018 the original author or authors.
+ * Copyright 2002-2019 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -598,10 +598,7 @@ public class RequestMappingHandlerAdapter extends AbstractHandlerMethodAdapter
 			if (!binderMethods.isEmpty()) {
 				this.initBinderAdviceCache.put(adviceBean, binderMethods);
 			}
-			if (RequestBodyAdvice.class.isAssignableFrom(beanType)) {
-				requestResponseBodyAdviceBeans.add(adviceBean);
-			}
-			if (ResponseBodyAdvice.class.isAssignableFrom(beanType)) {
+			if (RequestBodyAdvice.class.isAssignableFrom(beanType) || ResponseBodyAdvice.class.isAssignableFrom(beanType)) {
 				requestResponseBodyAdviceBeans.add(adviceBean);
 			}
 		}