Comment 1 for bug 2060103

The constraint is explicitly marked in the EC2 logic as unsupported, but we should support it.

This might be simple.

We construct an instance of ec2.RunInstancesInput to pass to runInstances.

This has a member NetworkInterfaces, which is a slice of InstanceNetworkInterfaceSpecification. We do not populate this.

That type has a member AssociatePublicIpAddress. If it is as simple as populating this and otherwise relying on defaults, we're good. If we have to fully construct it once opted in, maybe a little harder.