I have the below webview client which sets the user agent to a desktop browser when we are viewing a page that does not contain the word google in the URL. (Also does other
You can use setDesktopMode(true) from this WebView subclass or read how it's implemented in detail.
This way, you don't have to set a fixed user-agent string. Moreover, setting the user-agent string only is usually not enough. It depends on the site, of course, since every website uses their own way of determining whether the client is on mobile or desktop.