Add Parameter	fallbackToLocalRack : boolean in method protected chooseLocalStorage(localMachine Node, excludedNodes Set<Node>, blocksize long, maxNodesPerRack int, results List<DatanodeStorageInfo>, avoidStaleNodes boolean, storageType StorageType, fallbackToLocalRack boolean) : DatanodeStorageInfo from class org.apache.hadoop.hdfs.server.blockmanagement.BlockPlacementPolicyWithNodeGroup