In fact, google does return facebook as the first result when you search for "facebook"[1], and as for the install prompt that's something that facebook itself

In fact, google does return facebook as the first result when you search for "facebook"[1], and as for the install prompt that's something that facebook itself can show. [1]: https://www.google.com/search?q=facebook https://www.google.com/search?q=facebook