Remove temporary OAuth2AccessTokenResponseHttpMessageConverter

Issue gh-321

Closes gh-726

Author: jgrandja

oauth2-authorization-server/src/main/java/org/springframework/security/oauth2/server/authorization/web/OAuth2AccessTokenResponseHttpMessageConverter.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2020-2021 the original author or authors.
+ * Copyright 2020-2022 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.
@@ -42,6 +42,7 @@
 import org.springframework.security.oauth2.core.OAuth2RefreshToken;
 import org.springframework.security.oauth2.core.endpoint.OAuth2AccessTokenResponse;
 import org.springframework.security.oauth2.core.endpoint.OAuth2ParameterNames;
+import org.springframework.security.oauth2.core.http.converter.OAuth2AccessTokenResponseHttpMessageConverter;
 import org.springframework.security.oauth2.core.http.converter.OAuth2ErrorHttpMessageConverter;
 import org.springframework.security.oauth2.server.authorization.authentication.OAuth2AccessTokenAuthenticationToken;
 import org.springframework.security.oauth2.server.authorization.authentication.OAuth2AuthorizationCodeAuthenticationProvider;