@Override
    public Optional<InfraApplicationApi> getInfraApplication(ApplicationId applicationId) {
        return Optional.ofNullable(supportedInfraApplications.get(applicationId));
    }
Synchronously call {@link DuperModelListener#applicationActivated(ApplicationInfo) listener.applicationActivated()}
for each currently active application, and forward future changes.
service-monitor/src/main/java/com/yahoo/vespa/service/duper/DuperModelManager.java