[FEATURE] Add ai_gateway Terraform support for (non-external) Provisioned Throughput Foundation Model endpoints #5201
Description
Use-cases
Databricks provides additional controls (AI Gateway) for FM serving endpoints, and there is Terraform support for the ai_gateway block for external models, but not for built-in foundation models served by Provisioned Throughput endpoints.
Terraform should support built-in foundation models as well so that users can use IaC to stand up and govern endpoints for built-in and external FM endpoints.
Attempted Solutions
According to documentation, ai_gateway block is only for external models.
Proposal
Incorporate ai_gateway settings for built-in FM model configuration
References
#4029
https://docs.databricks.com/api/workspace/servingendpoints/putaigateway
https://registry.terraform.io/providers/databricks/databricks/latest/docs/resources/model_serving