Unwrap session before selecting stats counter

See gh-29375

spring-websocket/src/main/java/org/springframework/web/socket/messaging/SubProtocolWebSocketHandler.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2020 the original author or authors.
+ * Copyright 2002-2023 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.
@@ -47,6 +47,7 @@ import org.springframework.web.socket.WebSocketMessage;
 import org.springframework.web.socket.WebSocketSession;
 import org.springframework.web.socket.handler.ConcurrentWebSocketSessionDecorator;
 import org.springframework.web.socket.handler.SessionLimitExceededException;
+import org.springframework.web.socket.handler.WebSocketSessionDecorator;
 import org.springframework.web.socket.sockjs.transport.session.PollingSockJsSession;
 import org.springframework.web.socket.sockjs.transport.session.StreamingSockJsSession;
 
@@ -669,6 +670,7 @@ public class SubProtocolWebSocketHandler
 		}
 
 		AtomicInteger getCountFor(WebSocketSession session) {
+			session = WebSocketSessionDecorator.unwrap(session);
 			if (session instanceof PollingSockJsSession) {
 				return this.httpPolling;
 			}