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
'queryParameters' in Google BigQuery Jobs API:
        https://cloud.google.com/bigquery/docs/reference/rest/v2/jobs.
        For example, [{ 'name': 'corpus', 'parameterType': { 'type': 'STRING' },
        'parameterValue': { 'value': 'romeoandjuliet' } }]. (templated)
    :type query_params: list
    :param labels: a dictionary containing labels for the job/query,
        passed to BigQuery
    :type labels: dict
    :param priority: Specifies a priority for the query.
        Possible values include INTERACTIVE and BATCH.
        The default value is INTERACTIVE.
    :type priority: str
    :param time_partitioning: configure optional time partitioning fields i.e.
        partition by field, type and expiration as per API specifications.
    :type time_partitioning: dict
    :param cluster_fields: Request that the result of this query be stored sorted
        by one or more columns. BigQuery supports clustering for both partitioned and
        non-partitioned tables. The order of columns given determines the sort order.
    :type cluster_fields: list[str]
    :param location: The geographic location of the job. Required except for
        US and EU. See details at
        https://cloud.google.com/bigquery/docs/locations#specifying_your_location
    :type location: str
    :param encryption_configuration: [Optional] Custom encryption configuration (e.g., Cloud KMS keys).
        **Example**: ::
            encryption_configuration = {
                "kmsKeyName": "projects/testp/locations/us/keyRings/test-kr/cryptoKeys/test-key"
            }
    :type encryption_configuration: dict
    :param impersonation_chain: Optional service account to impersonate using short-term