Add ability to specify security group to use for running ECS tasks

[gaffer01]

Background

Some accounts are set up such that ECS tasks need to run with a security group in order to access ECR to obtain the images. Currently there is no way for the user to specify the security group to use to run the task.

Description

We'd like the user to be able to specify the security group to be used when any ECS tasks are run in the system.

Analysis

We can add an instance property for the security group. This can be applied to all the AwsVpcConfiguration objects in the code (RunCompactionTasks, RunIngestTasks, RunWriteRandomDataTaskOnECS). As the withSecurityGroups method on AwsVpcConfiguration takes multiple security groups, we can make the property a comma-separated list of security groups to be added.