title: Issues with Expo Auth Session implementation
body: <p>I am having issues with the implementation of Expo Auth Session.</p>
  
  <p>I am trying Google Oauth Login in Expo Auth Session as documented here: <a href="https://docs.expo.io/guides/authentication/#google" rel="noreferrer">https://docs.expo.io/guides/authentication/#google</a></p>
  
  <pre><code>WebBrowser.maybeCompleteAuthSession();
  
  const GoogleButton = () =&gt; {
    // Endpoint
    const discovery = useAutoDiscovery('https://accounts.google.com');
  
    // Request
    const [request, response, promptAsync] = useAuthRequest(
      {
        clientId: 'MYID',
        scopes: ['email', 'profile'],
        // For usage in managed apps using the proxy
        redirectUri: makeRedirectUri({
          // For usage in bare and standalone
          native: 'com.googleusercontent.apps.MYID://redirect',
          useProxy: true,
        }),
      },
      discovery,
    );
  
    console.log(request);
    console.log(response);
  
    return (
      &lt;Button
        onPress={promptAsync}
        icon={GoogleIcon}
      /&gt;
    );
  };
  </code></pre>
  
  <p>The browser opens, I can successfully log in with google, but when I get redirected to the app, response resolves to <code>Object { "type": "dismiss", }</code></p>
  
  <p>I also tried implementing oauth with a different oauth service:</p>
  
  <pre><code>WebBrowser.maybeCompleteAuthSession();
  
  const HiveButton = () =&gt; {
    // Endpoint
    const discovery = {
      authorizationEndpoint:
        'https://hivesigner.com/login-request/my.app',
    };
  
    // Request
    const [request, response, promptAsync] = useAuthRequest(
      {
        scopes: ['posting'],
        // For usage in managed apps using the proxy
        redirectUri: makeRedirectUri({
          useProxy: true,
        }),
      },
      discovery,
    );
  
    console.log(request);
    console.log(response);
  
    return (
      &lt;Button
        onPress={promptAsync}
        icon={HiveIcon}
      /&gt;
    );
  };
  </code></pre>
  
  <p>The browser opens, I can log in successfully, but instead of being redirected to the app, I get "Something went wrong trying to finish signing in. Please close this screen to go back to the app." on auth.expo.io/@me/myapp, even though the parameter code has the correct login token that I want to pass to my app.</p>