While this does fix the issue of Google search not sending a Material Design page to Firefox for Android, it does so in a way that makes Google think that Firefox for Android is insignificant compared to Chrome for Android.

A better way to do this would be to serve the Firefox for iOS User Agent string, because Firefox for iOS also receives the Material Design page. This is most likely because Firefox for iOS and Chrome for iOS are just glorified Safari skins.

Of course, switching to a third party search engine with a no tracking at all policy that doesn’t have its own browser that it would push by inconveniencing other browsers is a much better long term solution (like DuckDuckGo for example).