I interview a lot of junior, mid, and senior devs. Mostly for web dev and data sci roles now, but iOS in the past.
To be frank, macOS or iOS doesn't matter too much. For junior positions, I don't care much about what stack you have, because 1) it's almost never an immediate fill for what the company needs, and 2) there's still a lot about professional dev work that you'll have to learn on the job.
What I do care a lot about is 1) Are you capable of continually learning new things? 2) Are you driven to work really hard at learning things on your own?, and 3) Are you humble and hungry for guidance and feedback?
3 is handled by the interview. The best way to show 1 and 2, is by having a polished project in the App Store I can check out and play with. I don't expect it to be super popular or related to what my company does, but I do expect it to be something that you spent a lot of time on, that you built yourself (I.e. Not the contact app from a swift book or a school project), and that you can talk passionately about.
Focus on getting a project shipped and iterated, and you'll be good. No joke, if I'm interviewing for a junior iOS gig, I'd much rather take a non-cs kid who's built websites and can talk through the problems they had to solve, than a cs kid who has some iOS classes but only college projects in their portfolio.
tldr1 Don't worry, just ship something
tldr2 Don't even worry about learning android or other stacks yet, especially if it cuts into you shipping something. Learn what you're interested in, and ship.
tldr3 Except git - learn how to use github