HDDS-8683. Container balancer thread interrupt may not work (#6179)

hadoop-hdds/server-scm/src/main/java/org/apache/hadoop/hdds/scm/container/balancer/ContainerBalancer.java

@@ -342,10 +342,13 @@ private static void blockTillTaskStop(Thread balancingThread) {
     // NOTE: join should be called outside the lock in hierarchy
     // to avoid locking others waiting
     // wait for balancingThread to die with interrupt
-    balancingThread.interrupt();
     LOG.info("Container Balancer waiting for {} to stop", balancingThread);
     try {
-      balancingThread.join();
+      while (balancingThread.isAlive()) {
+        // retry interrupt every 5ms to avoid waiting when thread is sleeping
+        balancingThread.interrupt();
+        balancingThread.join(5);
+      }
     } catch (InterruptedException exception) {
       Thread.currentThread().interrupt();
     }