I would say 144mm is the maximum length of the phone. I have an S6 and it is 143.4mm in length and without a case it just squeezes in with the armrest providing a little pressure vertically. Thickness isn’t going to be a concern on phones, it fits fine with my case on in thickness. I am not sure on what the maximum width could be.
Also, if it is a little longer it will still probably work, you just won’t be able to close the armrest.
Also, if it is a little longer it will still probably work, you just won’t be able to close the armrest.