Revert "remove unecessary templated field (apache#36491)"

This reverts commit f070efa.

airflow/providers/google/cloud/transfers/bigquery_to_postgres.py

@@ -18,6 +18,8 @@
 """This module contains Google BigQuery to PostgreSQL operator."""
 from __future__ import annotations
 
+from typing import Sequence
+
 from airflow.providers.google.cloud.transfers.bigquery_to_sql import BigQueryToSqlBaseOperator
 from airflow.providers.postgres.hooks.postgres import PostgresHook
 
@@ -34,6 +36,8 @@ class BigQueryToPostgresOperator(BigQueryToSqlBaseOperator):
     :param postgres_conn_id: Reference to :ref:`postgres connection id <howto/connection:postgres>`.
     """
 
+    template_fields: Sequence[str] = (*BigQueryToSqlBaseOperator.template_fields, "dataset_id", "table_id")
+
     def __init__(
         self,
         *,