Authentificating datasource with grafana provisioning

The docs say, that the provisioning is similar to the Google Cloud Monitoring plugin for datasources
However it does not support privateKeyPath and/or all the other fields in jsonData.
Are they gonna be supported in the future?
Something like this does not work, even though the private key is mounted. The other fields such as defaultProject or clientEmail are not set as well.

```
- name: Google Cloud Logging
type: googlecloud-logging-datasource
access: proxy
jsonData:
tokenUri: tokenURI
clientEmail: email@project.gserviceaccount.com
authenticationType: jwt
defaultProject: projectName
privateKeyPath: /etc/secrets/privateKey.pem
```