[KYUUBI #1449][BACKPORT][FOLLOWUP] Fix import

### _Why are the changes needed?_

Fix import to pass CI

### _How was this patch tested?_
- [ ] Add some test cases that check the changes thoroughly including negative and positive cases if possible

- [ ] Add screenshots for manual tests if appropriate

- [x] [Run test](https://kyuubi.readthedocs.io/en/latest/develop_tools/testing.html#running-tests) locally before make a pull request

kyuubi-server/src/main/scala/org/apache/kyuubi/server/KyuubiServer.scala

@@ -35,7 +35,7 @@ import org.apache.kyuubi.ha.HighAvailabilityConf._
 import org.apache.kyuubi.ha.client.{ServiceDiscovery, ZooKeeperAuthTypes}
 import org.apache.kyuubi.ha.client.ZooKeeperClientProvider._
 import org.apache.kyuubi.metrics.{MetricsConf, MetricsSystem}
-import org.apache.kyuubi.service.{AbstractBackendService, AbstractFrontendService, Serverable}
+import org.apache.kyuubi.service.{AbstractBackendService, AbstractFrontendService, Serverable, ServiceState}
 import org.apache.kyuubi.util.{KyuubiHadoopUtils, SignalRegister}
 import org.apache.kyuubi.zookeeper.EmbeddedZookeeper