fix testGetServices ut

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

@@ -32,7 +32,6 @@ import static com.tencent.polaris.test.common.Consts.SERVICE_PROVIDER;
 import static java.util.Collections.singletonList;
 import static org.assertj.core.api.Assertions.assertThat;
 import static org.mockito.ArgumentMatchers.anyString;
-import static org.mockito.Mockito.doReturn;
 import static org.mockito.Mockito.mock;
 import static org.mockito.Mockito.when;
 
@@ -63,14 +62,12 @@ public class PolarisDiscoveryClientTest {
 
 	@Test
 	public void testGetServices() {
-
-//		when(polarisServiceDiscovery.getServices()).thenReturn(singletonList(SERVICE_PROVIDER));
-		doReturn(singletonList(SERVICE_PROVIDER)).when(polarisServiceDiscovery).getServices();
+		when(polarisServiceDiscovery.getServices()).thenReturn(singletonList(SERVICE_PROVIDER));
 
 		List<String> services = client.getServices();
 
-		assertThat(services).contains(SERVICE_PROVIDER).size().isEqualTo(1);
-
+		assertThat(services).size().isEqualTo(1);
+		assertThat(services.contains(SERVICE_PROVIDER)).isTrue();
 	}
 
 	@Test