title: Change AWS ECS service's security groups
body: <p>I would like to be able to modify the network configuration of an AWS ECS service.  The interface has "Allowed VPC", "Allowed subnets", "Security Groups", and "Auto-assign public IP" at the top of the "Configure network" screen.  However they cannot be modified.  We have been using a common security group for some of the services.  When creating one of the services we missed assigning the security group so a new one was created.  This seems like something I should be able to go back and correct.</p>