YARN-11357. Fix CheckStyle.

Author: slfan1989

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-router/src/test/java/org/apache/hadoop/yarn/server/router/clientrm/TestFederationClientInterceptorRetry.java

@@ -330,7 +330,7 @@ public void testSubmitApplicationTwoBadOneGood() throws Exception {
     // We will get bad1
     checkSubmitSubCluster(appId, bad1);
 
-    // Set the retryNum to 1
+    // Set the retryNum to 2
     // 1st time will use bad2, 2nd time will use bad1, 3rd good
     interceptor.setNumSubmitRetries(2);
     SubmitApplicationResponse submitAppResponse = interceptor.submitApplication(request);

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-router/src/test/java/org/apache/hadoop/yarn/server/router/clientrm/TestSequentialBroadcastPolicyManager.java

@@ -21,6 +21,14 @@
 import org.apache.hadoop.yarn.server.federation.policies.amrmproxy.BroadcastAMRMProxyPolicy;
 import org.apache.hadoop.yarn.server.federation.policies.manager.AbstractPolicyManager;
 
+/**
+ * This PolicyManager is used for testing and will contain the
+ * {@link TestSequentialRouterPolicy} policy.
+ *
+ * When we test FederationClientInterceptor Retry,
+ * we hope that SubCluster can return in a certain order, not randomly.
+ * We can view the policy description by linking to TestSequentialRouterPolicy.
+ */
 public class TestSequentialBroadcastPolicyManager extends AbstractPolicyManager {
   public TestSequentialBroadcastPolicyManager() {
     // this structurally hard-codes two compatible policies for Router and