That is legal as long as you don’t touch it while driving.
If the car has manufacturers hands-free fitted and that’s what you use then it should be acceptable.
Oh, that’s triggered my “getting out of SFO and onto the 280” PTSD.
If the phone is on a dash mount and already tuned in to a gps and/or audio stream, and hands free enabled telephone controlled on the wheel or dash, is all fine. You just cannot touch the phone. If there is a suspician that you touched it, they can, I understand, confiscate the phone and have the log forensically examined.
But hey, it is still ok to touch to your heart’s content, the huge touch screens fitted to many/most cars these days..,
My friend in the UK stopped at lights and was resting her head on her hand, a police car pulled up alongside her and claimed she was on her phone, " no, the phones in the back with my kids, they’ve been playing with it", " so", plod replied/ lied " I saw you throw your phone into the back when you saw us". How on earth was she going to prove it was the kids using the phone and not her?
Easy, the kids ( aged 5 and 7) were filming her driving.
Lucky she has tech savvy kids.
One hopes that not all police officers are as dishonest as this one.