title: Firestore transient condition issue
body: <p>I just upgraded my Flutter project dependencies to the latest version. After upgrading to the latest version it started throwing an exception whenever I try to fetch data from Firestore. However I am able to fetch data from a real time database.</p>
  <p><strong>Error</strong>:</p>
  <blockquote>
  <p>E/flutter ( 3036): [ERROR:flutter/lib/ui/ui_dart_state.cc(198)] Unhandled Exception: [cloud_firestore/unavailable] The service is currently unavailable. This is a most likely a transient condition and may be corrected by retrying with a backoff.</p>
  </blockquote>
  <p>Tried the following solutions:</p>
  <ol>
  <li>Wiped out the data from the Android emulator.</li>
  <li>Make sure the emulator is connected to the internet.</li>
  </ol>
  <p><strong>cloud_firestore: ^3.1.15</strong></p>