The original commit c9b7b1 ensured the ability to read parameterized type @RequestBody arguments via GenericHttpMessageConverter (e.g. application/json and List<String>). However, it also affected the ability to read @RequestBody arguments that happen are parameterized but aren't treated as such (e.g. application/x-www-form-urlencoded and MultiValueMap<String, String>). This commit corrects the issue. Issue: SPR-9570