private static Optional<InfrastructureApplication> childOf(InfrastructureApplication application) {
        return switch (application) {
            case CONFIG_SERVER_HOST -> Optional.of(InfrastructureApplication.CONFIG_SERVER);
            case CONTROLLER_HOST -> Optional.of(InfrastructureApplication.CONTROLLER);
            default -> Optional.empty();
        };
    }
Performs on-demand redeployment of the {@link InfrastructureApplication}s, to minimise time between
host provisioning for a deployment completing, and deployment of its application containers succeeding.

@author jonmv
node-repository/src/main/java/com/yahoo/vespa/hosted/provision/maintenance/InfraApplicationRedeployer.java