My view is you do what you need to do to get the result. We are suggesting this as a skill set for a job.
You will train in an art you hate if you need to get good at it. People do it all the time.
Oh and if there is a fitness test for the cops that involves running. And you don't like running. Go do swimming instead. Same thing really.
I realize that it's because the OP wants to work in law enforcement. That being said, assuming that martial arts is something that she wants to continue long term and not just for a short period, I think the advice to find one you like to practice rather than one you simply do because you think it will be the most effective is a sound one. You can push through you dislike for anything in the short term, but long term I generally find people don't work as hard at things they don't like. If you loathe your job do you do try as hard as the person who loves it? Probably not. Do people do passable jobs doing things they hate, sure. But I doubt they rarely truly excel at them. I'm not saying the OP should go out and pick Tai Chi and think she's going to be able to defend herself, but assuming there's good quality instruction for several different martial arts in her area, I think she will do better picking one she enjoys doing.
So if the person really hates running and wants to be a LEO they will train to run just as much as they need to pass the test and probably not much more. And they could very well use swimming to help them get ready for running. If they are an excellent swimmer that trains every day, they probably have the cardiovascular endurance to run fairly well with minimal training. By the same vein, if the OP trains a martial art they love they could probably use it to help them be effective in the martial arts skills their agency reaches them. If they only train in a martial art they hate, they will probably train it to up to the point of being passable.