HDFS-16478 Add thread id to command processor name

Provides additional clarity in logs when debugging MiniDFSCluster with
multiple in-process DataNodes.

Author: madrob

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/datanode/BPServiceActor.java

@@ -1378,7 +1378,7 @@ class CommandProcessingThread extends Thread {
     private final BlockingQueue<Runnable> queue;
 
     CommandProcessingThread(BPServiceActor actor) {
-      super("Command processor");
+      setName("Command processor-" + getId());
       this.actor = actor;
       this.queue = new LinkedBlockingQueue<>();
       setDaemon(true);