log query fails until query row is expanded

I just logged [this issue](https://github.com/grafana/grafana/issues/112075) with grafana, but I'm crossposting it here since it seems likely the bug is in this datasource. To briefly summarize the issue: When a request is sent to this datasource with the `query` field filled out but the `queryText` field empty, the datasource doesn't return any results.

I see that [there is special handling for these fields in one part of the datasource](https://github.com/GoogleCloudPlatform/cloud-logging-data-source-plugin/blob/51163c30e658336622ec6ea38c41a039d4837dc2/src/QueryEditor.tsx#L44), but it seems the request doesn't hit this code under certain conditions.

For more info see the original issue I filed with grafana: https://github.com/grafana/grafana/issues/112075

### Components:
- Grafana Cloud
- GCP Cloud logging v1.5.1