title: Enable Firebase offline persistence for web after Firebase object already being accessed
body: <p><strong>Encountered Error</strong>
  <br>Trying to enable offline persistence for web after accessing Firebase methods outputs the following error:</p>
  
  <pre><code>You can only call enablePersistence() before calling any other methods on a Firestore object.
  </code></pre>
  
  <p><strong>Context:</strong>
  <br>On initial PWA load user declined to enable offline support. So for this case I am looking for a possibilities to allow enable it afterwards.</p>
  
  <p><strong>Personal thoughts:</strong><br>
  I believe it should be possible to force a re-render of app with the framework that is currently used and temporary store the flag that will ask firebase to enable offline support. But I wonder if there is some Firebase SDK offers a solution that provides a possibility to achieve that more elegant way.</p>
  
  <p><strong>P.S</strong>: 
  <br>Additionally I wonder once offline persistence option was enabled is it save to believe that offline persistence will be enabled each time user opens PWA unless the PWA related data was removed from the device</p>