HADOOP-17612. Upgrade Zookeeper to 3.6.3 and Curator to 5.2.0

hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/security/token/delegation/ZKDelegationTokenSecretManager.java

@@ -343,10 +343,10 @@ public void startThreads() throws IOException {
         loadFromZKCache(true);
       } catch (Exception e) {
         throw new IOException("Could not start Curator tokenCacheListener for tokens", e);
-      } 
+      }
     }
     super.startThreads();
-  }  
+  }
   /**
    * Load the CuratorCache into the in-memory map. Possible caches to be
    * loaded are keyCache and tokenCache.

hadoop-hdfs-project/hadoop-hdfs-rbf/src/test/java/org/apache/hadoop/hdfs/server/federation/security/token/TestZKDelegationTokenSecretManagerImpl.java

@@ -101,6 +101,7 @@ public void testMultiNodeOperationWithoutWatch() throws Exception {
     }
   }
 
+  @SuppressWarnings("unchecked")
   @Test
   public void testMultiNodeTokenRemovalShortSyncWithoutWatch()
       throws Exception {