With support from a helpful Databricks employee, we found out that the problem was that the `private_key` / `private_key_plaintext` field needs to be the entire JSON object that GCP creates for the service account not just the private key string from...
With support from a helpful Databricks employee, we found out that the problem was that the `private_key` / `private_key_plaintext` field needs to be the entire JSON object that GCP creates for the service account not just the private key string from...