title: Force refresh of manifest.json to download new PWA
body: <p>I have a <strong>start_url</strong> set to <code>/mysite</code>. Now I've updated the manifest to have <strong>start_url</strong> set to <code>/mysite?tracking=ga</code> in order to view installs from the app.</p>
  <p>Anyway for the life of me I can't figure out how to force a download of the new app, the app is still pointing to the old <code>start_url</code>.  I know how to update a service worker and thus Cache API or any other caches but do not have a reliable method to force a refresh of <code>manifest.json</code> and thus force a new download of the apk.  Even when I delete the apk and download a new app through &quot;Add to Homescreen&quot; it points to the old `start_url.  My understanding is that every manifest requires a new apk.</p>
  <p>*Update: Did multiple tests where I updated the manifest theme_color and the only way to see the changes is to uninstall the app and clear Chrome cache and data completely, then reinstall through &quot;Add to home screen&quot; prompt.</p>