Apply suggestion from @gemini-code-assist[bot]

Co-authored-by: gemini-code-assist[bot] <176961590+gemini-code-assist[bot]@users.noreply.github.com>

Author: agrawalradhika-cell

packages/google-auth/google/auth/transport/grpc.py

@@ -17,7 +17,9 @@
 from __future__ import absolute_import
 
 import logging
-import threading
+import logging
+
+_LOGGER = logging.getLogger(__name__)
 from google.auth import exceptions
 from google.auth.transport import _mtls_helper
 from google.oauth2 import service_account