**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
bq_hook = BigQueryHook(
            gcp_conn_id=self.bigquery_conn_id,
            delegate_to=self.delegate_to,
            location=self.location,
            impersonation_chain=self.impersonation_chain,
        )
        if not self.schema_fields and self.schema_object and self.source_format != 'DATASTORE_BACKUP':
            gcs_hook = GCSHook(
                google_cloud_storage_conn_id=self.google_cloud_storage_conn_id,
                delegate_to=self.delegate_to,
                impersonation_chain=self.impersonation_chain,
            )
            schema_object = gcs_hook.download(self.bucket, self.schema_object)
            schema_fields = json.loads(schema_object.decode("utf-8"))
        else: