I think this was ~4 minutes worth of exposure time. I took this with my Pixel phone and Google's astrophotography mode, which is part of the Night Sight setting. When the phone realizes it's completely still, like on a tripod, and it's looking at the sky, it gives you the option of taking pictures like this. It actually takes a lot of short exposures and stacks them. It's a very automated process, so there's not much tweaking to do. I do wish they gave the user more control.
The setup for this picture was just my Pixel 6 Pro on a tripod pointing up. :)
I think so, but I'm not sure how. I think some other phones are compatible and will 'just work' with Google's camera app. Others need some configuration with 3rd party software. I've never done it.