Remove error log entry on clean BiDi shutdown. (#8806)
Remove error log entry on clean BiDi shutdown. (#8806)

Closes #8803.
GoogleCloudPlatform/gcloud-python,tswast/google-cloud-python,googleapis/google-cloud-python,tseaver/google-cloud-python,googleapis/google-cloud-python,tseaver/google-cloud-python,GoogleCloudPlatform/gcloud-python,tswast/google-cloud-python,tswast/google-cloud-python,tseaver/google-cloud-python