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
tests/providers/google/cloud/operators/test_bigquery.py
with self.dag:
            BigQueryExecuteQueryOperator(
                task_id=TASK_ID,
                sql=['SELECT * FROM test_table', 'SELECT * FROM test_table2'],
            )
        serialized_dag = SerializedDAG.to_dict(self.dag)
        self.assertIn("sql", serialized_dag["dag"]["tasks"][0])
        dag = SerializedDAG.from_dict(serialized_dag)
        simple_task = dag.task_dict[TASK_ID]
        self.assertEqual(
            getattr(simple_task, "sql"), ['SELECT * FROM test_table', 'SELECT * FROM test_table2']
        )
        
        
        
        
        self.assertEqual(
            serialized_dag["dag"]["tasks"][0]["_operator_extra_links"],
            [
                {