[AIRFLOW-5519] Fix sql_to_gcs operator missing multi-level default args by adding apply_defaults decorator

[yimingl17]

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Jira

• My PR addresses the following Airflow Jira issues and references them in the PR title.
  • https://issues.apache.org/jira/browse/AIRFLOW-5519

Description

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  The apply_defaults decorator is missing in sql_to_gcs operator (BaseSQLToGoogleCloudStorageOperator), which will cause missing multi-level default args such as google_cloud_storage_conn_id.

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