YARN-9424. Change getDeclaredMethods to getMethods in FederationClientInterceptor#invokeConcurrent. Contributed by Shen Yinjie.

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-router/src/main/java/org/apache/hadoop/yarn/server/router/clientrm/FederationClientInterceptor.java

@@ -622,7 +622,7 @@ public class FederationClientInterceptor
           ApplicationClientProtocol protocol =
               getClientRMProxyForSubCluster(subClusterId);
           Method method = ApplicationClientProtocol.class
-              .getDeclaredMethod(request.getMethodName(), request.getTypes());
+              .getMethod(request.getMethodName(), request.getTypes());
           return method.invoke(protocol, request.getParams());
         }
       });