Firstly, I have to say German Shepherds are possibly not the best dogs for apartments. They can be aggressive/defensive and will bark when they hear people near your unit door. That cute puppy is going to grow into a large, smart, energetic and demanding animal.
However, the owners corp can’t force you to remove the dog right now. But they can ask and if you refuse that will probably count against you when it comes to their decision.
What you need to do is address their possible concerns, for instance:
* by offering not to enter the lift with the dog when other people are already inside,
* to have the dog on a leash and muzzle whenever you take it through common property,
* to satisfactorily complete dog training classes with the pup,
* to ensure it is never left alone in the apartment (the main cause of excessive barking)
If you can fulfill all these commitments, the committee will find it hard to reasonably refuse your request (although you may have to fight them at NCAT if they do).
You can also point out that, if the worst comes to the worst, the owners corporation has an avenue, under Section 158 of the strata Act, to require the removal of a dog that has been permitted but has proved to be troublesome, so it’s not as if you are asking for carte blanche permission, come what may.
Meanwhile, only NCAT can order the removal of the puppy and the fact that you were originally given wrong information by the building manager gives you a strong case for keeping the pooch until such times as this is resolved.