This is an interesting question. I have an eight-months-old Labrador at the moment, so I clean up after (and preemptively apologize for) a dog on a daily basis. He’s a good dog, but he’s young, and he has lots of creative ideas.
I believe all dog owners share the responsibility of making sure no-one is bothered by a dog which does not belong to them. This includes keeping your dog from barking excessively, as well as making sure he does not scare people, chase animals, damage property, or frighten other dogs.
However, there is only so much an owner can do. Jumping up is my go-to example. Yes, it is very possible to train dogs to not jump on people. They can even learn not to jump up when guests come, and when children bounce around in excitement. They can, theoretically, also learn not to jump up when there are treats being waved just out of reach, and taunting people spur them on. Why do they have to, though? Can’t we try to make things just a tiny bit easier, by not actively encouraging bad behavior?
This is relevant to your issue. Of course cleaning up after your dog is your responsibility – but your roommate should make it her responsibility to not create extra work for you.