Service reference gets rewritten in tests and thus instance is not correctly registered into OSGi

bgpcep/integration-tests/src/test/resources/controller.xml
sometimes triggers failure on waiting for BindingAware service in org.opendaylight.protocol.integration.pcep.PcepRpcServicesRoutingTest, namely on https://git.opendaylight.org/gerrit/#/c/6099/

There are two issues:

automatic storing of references in netconf (with ref_ prefix)

org.opendaylight.controller.config.manager.impl.ServiceReferenceRegistryImpl#modulesToServiceRef map should allow multiple annotations with same name - internal map should be wrapped.