Expose autoscaling parameters in Notebook EMR cluster

[adrianisk]

Feature Request

I imagine we're going to want to enable autoscaling on the Notebook EMR cluster created by the terraform modules in this repo. It would be great if the notebook_cluster module exposed an autoscaling_policy variable that was then plumbed through to the aws_emr_cluster resource created at https://github.com/tecton-ai-ext/tecton-terraform-setup/blob/e7fabd83ed602988ecd5d285f69dad3e7dd365ab/emr/notebook_cluster/main.tf#L80 We might also want/need to expose the autoscaling_role and auto_termination_policy properties.

aws_emr_cluster resource documentation

[adrianisk]

This change is pretty straightforward. If you're onboard with the change I don't mind taking a crack at it when I'm setting up our terraform later this week.

[scottames]

@adriank-convoy - if you want to take a crack at it, please do! Your proposal sounds good to me. The only thing I would suggest is that the variable is not required, and if not specified will be passed as a null value. Feel free to work with @davidhershey to connect with me on Slack if you have any further questions.