Use asg's launch template's `image_id` to directly resolve an upstream image from an ssm param

[nitrocode]

Describe the Feature

https://registry.terraform.io/providers/hashicorp/aws/latest/docs/resources/launch_template#image_id-1

image_id - (Optional) The AMI from which to launch the instance or use a Systems Manager parameter convention e.g. resolve:ssm:parameter-name. See docs for more details.

The cloudposse asg module already supports this.

We should be able to modify this

terraform-aws-ecs-cluster/ec2.tf

Lines 1 to 4 in e8625ab

	data "aws_ssm_parameter" "ami" {
	count = local.enabled ? 1 : 0
	name = "/aws/service/ecs/optimized-ami/amazon-linux-2/recommended/image_id"
	}

and this

terraform-aws-ecs-cluster/ec2.tf

Line 48 in e8625ab

image_id = each.value["image_id"] == null ? join("", data.aws_ssm_parameter.ami[*].value) : each.value["image_id"]

with

variable "ssm_image_id" {
  default = "/aws/service/ecs/optimized-ami/amazon-linux-2/recommended/image_id"
}

data "aws_ssm_parameter" "ami" {
  count = local.enabled ? 1 : 0
- name  = "/aws/service/ecs/optimized-ami/amazon-linux-2/recommended/image_id"
+ name  = var.ssm_image_id

- image_id      = each.value["image_id"] == null ? join("", data.aws_ssm_parameter.ami[*].value) : each.value["image_id"]
+ image_id      = each.value["image_id"] == null ? "resolve:ssm:${var.ssm_image_id}" : each.value["image_id"]

Expected Behavior

Use resolve:ssm directly in the launch template

Use Case

This allows us to never have to update the AMI again since the launch template will always use the latest that resolves in the upstream SSM parameter value

Describe Ideal Solution

Described above

Alternatives Considered

No response

Additional Context

No response