**Apache Airflow version**: 1.10.*
**BackPort Packages version**: 2020.10.5rc1

**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/apache/airflow/blob/master/airflow/providers/google/cloud/operators/bigquery.py#L2072

However, because BigQuery only accepts alphanumeric (in additon to dashes and underscore) characters then, if a DagID contains a version number whcih includes a `.` character then this will cause the task to fail.

https://cloud.google.com/bigquery/docs/running-jobs#generate-jobid

**How to reproduce it**:
Create a DAG with the name `my-dag-v1.0`.
airflow/providers/google/cloud/operators/bigquery.py
:param field_delimiter: The delimiter to use for the CSV.
    :type field_delimiter: str
    :param max_bad_records: The maximum number of bad records that BigQuery can
        ignore when running the job.
    :type max_bad_records: int
    :param quote_character: The value that is used to quote data sections in a CSV file.
    :type quote_character: str
    :param allow_quoted_newlines: Whether to allow quoted newlines (true) or not (false).
    :type allow_quoted_newlines: bool
    :param allow_jagged_rows: Accept rows that are missing trailing optional columns.
        The missing values are treated as nulls. If false, records with missing trailing
        columns are treated as bad records, and if there are too many bad records, an
        invalid error is returned in the job result. Only applicable to CSV, ignored
        for other formats.
    :type allow_jagged_rows: bool
    :param bigquery_conn_id: (Optional) The connection ID used to connect to Google Cloud and
        interact with the Bigquery service.
    :type bigquery_conn_id: str
    :param google_cloud_storage_conn_id: (Optional) The connection ID used to connect to Google Cloud
        and interact with the Google Cloud Storage service.
    :type google_cloud_storage_conn_id: str
    :param delegate_to: The account to impersonate using domain-wide delegation of authority,
        if any. For this to work, the service account making the request must have
        domain-wide delegation enabled.
    :type delegate_to: str
    :param src_fmt_configs: configure optional fields specific to the source format
    :type src_fmt_configs: dict
    :param labels: a dictionary containing labels for the table, passed to BigQuery
    :type labels: dict
    :param encryption_configuration: [Optional] Custom encryption configuration (e.g., Cloud KMS keys).