HDDS-1350. Fix checkstyle issue in TestDatanodeStateMachine. Contributed by Xiaoyu Yao. (#656)

hadoop-hdds/container-service/src/test/java/org/apache/hadoop/ozone/container/common/TestDatanodeStateMachine.java

@@ -16,7 +16,6 @@
  */
 package org.apache.hadoop.ozone.container.common;
 
-import com.google.common.base.Supplier;
 import com.google.common.collect.Maps;
 import com.google.common.util.concurrent.ThreadFactoryBuilder;
 import org.apache.hadoop.conf.Configuration;