Add dependency support for direct mbeans.

[WFLY-3921]; 
We should be able to depend on existing mbeans from jboss-service.xml.
(e.g. mbeans registered directly from JMX API)
This shouldn't be necessary. In start(StartContext startContext) you can get the service container via:

startContext.getController().getServiceContainer()

I'm surprised this doesn't deadlock boot, since FutureServiceContainer.get() shouldn't return until BootstrapListener.printBootStatistics() is called and that shouldn't happen until the boot ops that install this service complete.