servlet-galleon-pack is not overwriting core-galleon-pack resources

The servlet-galleon-pack should overwrite the resources incorporated from the wildfly-core-galleon pack. An example of this is the model.xml incorporated by the servlet distribution which must overwrite the one brought in by the core galleon pack. 

Although we do not distribute the servlet galleon pack, this bug akes servlet-dist fail their verifications when we are using core 15.0.x together with 7.4.x.