Containers on GCE are just higher-level configurations that Google exposes on the console and on gcloud. There is no API for that, internally the console and gcloud creates instances with Container-optimized OS and a startup-script that initiates the container that you specified: https://cloud.google.com/compute/docs/instances/create-start-instance#from-container-image
The module the made for terraform does just that too. It translates a smaller and more concise API into the generic one. You can make a Component on pulumi that does the same thing.