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
"query": {
                "query": "SELECT * FROM any",
                "useLegacySql": False,
            }
        }
        mock_hook.return_value.insert_job.return_value = MagicMock(job_id=real_job_id, error_result=True)
        op = BigQueryInsertJobOperator(
            task_id="insert_query_job",
            configuration=configuration,
            location=TEST_DATASET_LOCATION,
            job_id=job_id,
            project_id=TEST_GCP_PROJECT_ID,
        )
        with pytest.raises(AirflowException):
            op.execute({})
    @mock.patch('airflow.providers.google.cloud.operators.bigquery.hashlib.md5')
    @mock.patch('airflow.providers.google.cloud.operators.bigquery.BigQueryHook')
    def test_execute_reattach(self, mock_hook, mock_md5):
        job_id = "123456"
        hash_ = "hash"
        real_job_id = f"{job_id}_{hash_}"
        mock_md5.return_value.hexdigest.return_value = hash_
        configuration = {
            "query": {
                "query": "SELECT * FROM any",
                "useLegacySql": False,
            }
        }
        mock_hook.return_value.insert_job.return_value.result.side_effect = Conflict("any")
        job = MagicMock(