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
schema_fields = self.schema_fields
        if schema_fields and self.table_resource:
            self.table_resource["externalDataConfiguration"]["schema"] = schema_fields
        if self.table_resource:
            tab_ref = TableReference.from_string(self.destination_project_dataset_table)
            bq_hook.create_empty_table(
                table_resource=self.table_resource,
                project_id=tab_ref.project,
                table_id=tab_ref.table_id,
                dataset_id=tab_ref.dataset_id,
            )
        else:
            source_uris = [f"gs://{self.bucket}/{source_object}" for source_object in self.source_objects]
            bq_hook.create_external_table(
                external_project_dataset_table=self.destination_project_dataset_table,
                schema_fields=schema_fields,
                source_uris=source_uris,
                source_format=self.source_format,
                compression=self.compression,
                skip_leading_rows=self.skip_leading_rows,
                field_delimiter=self.field_delimiter,
                max_bad_records=self.max_bad_records,
                quote_character=self.quote_character,
                allow_quoted_newlines=self.allow_quoted_newlines,
                allow_jagged_rows=self.allow_jagged_rows,
                src_fmt_configs=self.src_fmt_configs,
                labels=self.labels,
                encryption_configuration=self.encryption_configuration,
            )
class BigQueryDeleteDatasetOperator(BaseOperator):