BigQuery component not working with custom QueryJobConfig

[parthmishra]

What happened:
If you pass in a dict for job_config, it's never actually converted into a QueryJobConfig type object that is required by the BigQuery client library. I'm also not able to pass in an object of type QueryJobConfig since job_config requires a dict. Because just the dict gets passed to the client.query() call, I end up with the following error:

Traceback (most recent call last):
  File "/usr/local/lib/python2.7/runpy.py", line 174, in _run_module_as_main
    "__main__", fname, loader, pkg_name)
  File "/usr/local/lib/python2.7/runpy.py", line 72, in _run_code
    exec code in run_globals
  File "/ml/kfp_component/launcher/__main__.py", line 34, in <module>
    main()
  File "/ml/kfp_component/launcher/__main__.py", line 31, in main
    launch(args.file_or_module, args.args)
  File "kfp_component/launcher/launcher.py", line 45, in launch
    return fire.Fire(module, command=args, name=module.__name__)
  File "/usr/local/lib/python2.7/site-packages/fire/core.py", line 127, in Fire
    component_trace = _Fire(component, args, context, name)
  File "/usr/local/lib/python2.7/site-packages/fire/core.py", line 366, in _Fire
    component, remaining_args)
  File "/usr/local/lib/python2.7/site-packages/fire/core.py", line 542, in _CallCallable
    result = fn(*varargs, **kwargs)
  File "kfp_component/google/bigquery/_query.py", line 67, in query
    query_job = client.query(query, job_config, job_id=job_id)
  File "/usr/local/lib/python2.7/site-packages/google/cloud/bigquery/client.py", line 1437, in query
    query_job = job.QueryJob(job_ref, query, client=self, job_config=job_config)
  File "/usr/local/lib/python2.7/site-packages/google/cloud/bigquery/job.py", line 2298, in __init__
    if job_config.use_legacy_sql is None:
AttributeError: 'dict' object has no attribute 'use_legacy_sql'

What did you expect to happen:
The job_config dict should be cast to QueryJobConfig object using .from_api_repr() or allowing a QueryJobConfig object to be passed directly since I don't believe this happens automatically in the client library.

Am I doing this incorrectly?