That's not an ad -- it's a normal function of the Google app. It can tell if you're near a particular establishment and offer up things like reviews, menus, etc. It'll show up for other places as well, like Target. I'm not sure if there's an easy way to turn that off. I couldn't find anything in the Google app's settings, but it might be in the Google Maps settings. There's an option for Personal Content>Web & App Activity there -- you could try turning that off.