align to checkstyle

spring-cloud-starter-tencent-polaris-discovery/src/main/java/com/tencent/cloud/polaris/registry/PolarisServiceRegistryAutoConfiguration.java

@@ -27,6 +27,7 @@ import com.tencent.cloud.polaris.registry.graceful.GracefulServiceRegistrationAu
 import com.tencent.cloud.polaris.registry.graceful.GracefulServiceRegistrationConfiguration;
 import com.tencent.cloud.polaris.registry.graceful.GracefulServiceRegistrationProperties;
 import com.tencent.polaris.client.api.SDKContext;
+
 import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.boot.autoconfigure.AutoConfigureAfter;
 import org.springframework.boot.autoconfigure.condition.ConditionalOnBean;

spring-cloud-starter-tencent-polaris-discovery/src/main/java/com/tencent/cloud/polaris/registry/graceful/AbstractGracefulServiceRegistration.java

@@ -7,6 +7,7 @@ import javax.annotation.PreDestroy;
 
 import org.apache.commons.logging.Log;
 import org.apache.commons.logging.LogFactory;
+
 import org.springframework.beans.BeansException;
 import org.springframework.boot.context.event.ApplicationReadyEvent;
 import org.springframework.boot.web.context.ConfigurableWebServerApplicationContext;

spring-cloud-starter-tencent-polaris-discovery/src/test/java/com/tencent/cloud/polaris/registry/PolarisGracefulServiceRegistrationTest.java

@@ -24,6 +24,7 @@ import org.junit.Test;
 import org.junit.runner.RunWith;
 import org.mockito.Mock;
 import org.mockito.junit.MockitoJUnitRunner;
+
 import org.springframework.cloud.client.serviceregistry.Registration;
 import org.springframework.cloud.client.serviceregistry.ServiceRegistry;
 import org.springframework.context.ApplicationContext;