title: PWA loses its params and query params after being added to the home screen
body: <p>I have created a PWA(Progressive Web App) using Angular6. It works perfectly as expected in the browser. My scenario is to handle all the app data based on the params I get from URL</p>
  
  <p>eg: <code>https://&lt;my-site.com&gt;/app/abc123</code></p>
  
  <p>where <code>abc123</code> is my param which I need to add to the home screen app.</p>
  
  <p>So the problem is when user adds the app to the home screen it loses all the params (I have tried using queryparams as well) and that leaves me only with the hostname. I need the whole URL to be added as the App URL. Can you please help.</p>
  
  <p>Thank you for your time and help!   </p>