create-instance-group action resets firewall rules updated by setup-firewall

[learnitall]

The setup-firewall action modifies rules deployed by kops to fit Cilium's requirements, however these changes are reset whenever the create-instance-group action is executed. Let's adjust the setup-firewall action to create a new firewall rule that kops won't be able to modify. We'll have to make sure that the rule is cleaned up afterwards as well.