**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/hooks/bigquery.py
self,
        external_project_dataset_table: str,
        schema_fields: List,
        source_uris: List,
        source_format: str = 'CSV',
        autodetect: bool = False,
        compression: str = 'NONE',
        ignore_unknown_values: bool = False,
        max_bad_records: int = 0,
        skip_leading_rows: int = 0,
        field_delimiter: str = ',',
        quote_character: Optional[str] = None,
        allow_quoted_newlines: bool = False,
        allow_jagged_rows: bool = False,
        encoding: str = "UTF-8",
        src_fmt_configs: Optional[Dict] = None,
        labels: Optional[Dict] = None,
        encryption_configuration: Optional[Dict] = None,
        location: Optional[str] = None,
        project_id: Optional[str] = None,
    ) -> None:
        """
        Creates a new external table in the dataset with the data from Google
        Cloud Storage. See here:
        https://cloud.google.com/bigquery/docs/reference/rest/v2/tables#resource
        for more details about these parameters.
        :param external_project_dataset_table:
            The dotted ``(<project>.|<project>:)<dataset>.<table>($<partition>)`` BigQuery