Ah - it's a system app and can't be uninstalled without rooting the phone.
Additionally I have noticed that with some vehicles it seems to Force the use of Android Auto or Apple Car Play to "ensure safety" and lock out things like Texting while driving.
As mentioned, the best you can do at this point is to disable it.
I have read, however, that in some vehicles, even that is not an option.
Myself, I tried out Android Auto on a previous phone and I didn't like it either because I didn't like the Texting to be completely locked out while I was idle at a stop light or in backed up traffic. And I didn't like the phone being forced into Landscape mode, since I personally prefer to use Google Maps in Portrait mode.
I do, however, realize that in the near future, with my next vehicle, I will have to accept that if I link my phone to the vehicle, I will be forced to use Android Auto. I only hope that at that point it will be a bit more customizable and at least allow the use of the phone in Portrait Mode instead of forcing Landscape Mode.