Imagen3 support

[affanshahid]

Does langchain-google not work with imagen-3.0-generate-002? I get the following error:

google.api_core.exceptions.NotFound: 404 models/imagen-3.0-generate-002 is not found for API version v1beta, or is not supported for generateContent.

It does make sense since imagen needs to be called with generate_images. Is support planned for images?

I understand Vertex supports imagen but I want to call the model using an API key (which is possible directly with the API) instead of using GCP configurations.