private Collection<RemoteSession> preparedAndActivatedSessions() {
        var tenantRepository = applicationRepository.tenantRepository();
        return tenantRepository.getAllTenantNames().stream()
                .map(tenantRepository::getTenant)
                .map(t -> t.getSessionRepository().getRemoteSessions())
                .flatMap(Collection::stream)
                .filter(s -> s.getStatus() == PREPARE || s.getStatus() == ACTIVATE)
                .toList();
    }
Verifies that all active sessions has an application package on local disk.
If not, the package is downloaded with file distribution. This can happen e.g.
if a config server is down when the application is deployed. This maintainer should only be run
if there is more than 1 config server

@author gjoranv
configserver/src/main/java/com/yahoo/vespa/config/server/maintenance/ApplicationPackageMaintainer.java