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
task_id='BigQueryCreateEmptyTableOperator_task',
                dataset_id='ODS',
                table_id='Employees',
                project_id='internal-gcp-project',
                gcs_schema_object='gs://schema-bucket/employee_schema.json',
                bigquery_conn_id='airflow-conn-id',
                google_cloud_storage_conn_id='airflow-conn-id'
            )
        **Corresponding Schema file** (``employee_schema.json``): ::
            [
              {
                "mode": "NULLABLE",
                "name": "emp_name",
                "type": "STRING"
              },
              {
                "mode": "REQUIRED",
                "name": "salary",
                "type": "INTEGER"
              }
            ]
        **Example (with schema in the DAG)**: ::
            CreateTable = BigQueryCreateEmptyTableOperator(
                task_id='BigQueryCreateEmptyTableOperator_task',
                dataset_id='ODS',
                table_id='Employees',
                project_id='internal-gcp-project',
                schema_fields=[{"name": "emp_name", "type": "STRING", "mode": "REQUIRED"},
                               {"name": "salary", "type": "INTEGER", "mode": "NULLABLE"}],
                bigquery_conn_id='airflow-conn-id-account',