Google Street View updated with iPhone X support, more1
Fortunately, that's a thing of the past since Google has just released a new version of the app and already uploaded it in the App Store. If you download Google Street View version 2.13.3 and fire it up, you'll notice that it's now displaying correctly on the iPhone X.
The information is confirmed by the official changelog as well, which also mentions that the update should bring some improvements for rendering 360-degree panoramas.
Ultimately, although Google took its time to add iPhone X support to its Street View app, it's definitely better to have it later than never.