Spring Security DefaultOAuth2AuthorizationRequestResolver erroneously consumes POST request body

Describe the bug DefaultOAuth2AuthorizationRequestResolver consumes the request body, by calling getParameter on the request, even if the request doesn't match the authorization request base uri.

The bug is in resolve(HttpServletRequest request) method, which calls getAction, even if the registrationId is null.

To Reproduce Create a filterchain with DefaultOAuth2AuthorizationRequestResolver in it. Send a POST request with a body. Observe that in the servlet, the request body appears to be empty.

Expected behavior I expect that the body doesn't appear to be empty.

Sample No sample, but I'm adding a PR with a test.

Comment From: eamelink

OAuth2AuthorizationCodeGrantFilter has a similar issue.