[CodeStyle][PeerQueueTest]TimeUnit seperated from previous import

dolphinscheduler-service/src/test/java/queue/PeerTaskInstancePriorityQueueTest.java

@@ -20,7 +20,9 @@ package queue;
 import org.apache.dolphinscheduler.common.enums.Priority;
 import org.apache.dolphinscheduler.dao.entity.TaskInstance;
 import org.apache.dolphinscheduler.service.queue.PeerTaskInstancePriorityQueue;
+
 import java.util.concurrent.TimeUnit;
+
 import org.junit.Assert;
 import org.junit.Test;