fix syntax/conflict residue and formatting issues in gapic_v1

Author: hebaalazzeh

packages/google-api-core/tests/conftest.py

@@ -14,6 +14,7 @@
 
 import os
 from unittest import mock
+
 import pytest
 
 

packages/google-api-core/tests/unit/gapic/test_client_utils.py

@@ -17,13 +17,14 @@
 import pytest
 from google.auth.exceptions import MutualTLSChannelError
 from google.auth.transport import mtls
+
 from google.api_core.gapic_v1.client_utils import (
     get_api_endpoint,
+    get_client_cert_source,
     get_default_mtls_endpoint,
     get_universe_domain,
-    get_client_cert_source,
-    use_client_cert_effective,
     read_environment_variables,
+    use_client_cert_effective,
 )