Apache Airflow version: 1.10.*
BackPort Packages version: 2020.10.29rc1

What happened:

BigQueryInsertJobOperator tries to start a BigQuery job by specifying a job_id which is a combination of dag_id, task_id, execution_date and an additional uniqueness_suffix.

https://github.com/PolideaInternal/airflow/blob/e5307990adb49a5a1c1c88a029940682efee0f9e/airflow/providers/google/cloud/operators/bigquery.py#L2073

However, it would appear that the regex pattern that is attempting to remove the `+` character is not correct as this still remain in `job_id` after `re.sub` is applied.

https://github.com/PolideaInternal/airflow/blob/e5307990adb49a5a1c1c88a029940682efee0f9e/airflow/providers/google/cloud/operators/bigquery.py#L2073

`Invalid job ID "airflow_my_test_dag_v1_test_2020_10_01T00_00_00+00_00_27f69de5cd17a012f3c89d414a70fe64". Job IDs must be alphanumeric (plus underscores and dashes) and must be at most 1024 characters long.
`  

How to reproduce it:

- Create a DAG with the name my-test-dag-v1.
- Run any query against BigQuery using this operator
airflow/providers/google/cloud/operators/bigquery.py
gcs_bucket, gcs_object = _parse_gcs_url(self.gcs_schema_object)
            gcs_hook = GCSHook(
                google_cloud_storage_conn_id=self.google_cloud_storage_conn_id,
                delegate_to=self.delegate_to,
                impersonation_chain=self.impersonation_chain,
            )
            schema_fields = json.loads(gcs_hook.download(gcs_bucket, gcs_object))
        else:
            schema_fields = self.schema_fields
        try:
            self.log.info('Creating table')
            table = bq_hook.create_empty_table(
                project_id=self.project_id,
                dataset_id=self.dataset_id,
                table_id=self.table_id,
                schema_fields=schema_fields,
                time_partitioning=self.time_partitioning,
                cluster_fields=self.cluster_fields,
                labels=self.labels,
                view=self.view,
                encryption_configuration=self.encryption_configuration,
                table_resource=self.table_resource,
                exists_ok=False,
            )
            self.log.info(
                'Table %s.%s.%s created successfully', table.project, table.dataset_id, table.table_id
            )
        except Conflict:
            self.log.info('Table %s.%s already exists.', self.dataset_id, self.table_id)
class BigQueryCreateExternalTableOperator(BaseOperator):