Add ecs-init build tag argument in integrated spec files

[fierlion]

Summary

This adds the build tag to the ecs-init gobuild.sh script, which will point to the correct ecs-init config
https://github.com/aws/amazon-ecs-init/blob/5f7f9336bc3c5314206aefd212e9ebbfc3bdab60/ecs-init/config/config_al2.go#L1

Implementation details

the tags are already defined in the spec files, this was just a miss in our setup/testing.

Testing

Built using make generic-rpm-integrated on a fresh instance of latest ecs-optimized AMI.

sudo systemctl stop ecs
sudo rpm -e <old rpm file>
sudo rpm -i <built rpm file>
sudo systemctl start ecs

then a docker inspect of the launched agent container to be sure we see:

            {
                "Type": "bind",
                "Source": "/sys/fs/cgroup",
                "Destination": "/sys/fs/cgroup",
                "Mode": "",
                "RW": true,
                "Propagation": "rprivate"
            },

Description for the changelog

Fix ecs-init build tag bug for integrated builds.

Licensing

By submitting this pull request, I confirm that my contribution is made under the terms of the Apache 2.0 license.

[YashdalfTheGray]

Good catch on this!