title: `result.isCancelled` + `result.postId` always undefined after cancellation via ShareDialog on Android
body: <p>I am attempting to utilize the ShareDialog export from the 'react-native-fbsdk' library.</p>
  
  <p>Our implementation (shown below) works perfectly well when the user doesn't have Facebook installed on their device and when they successfully share their photo.</p>
  
  <p>However, when the user begins to share and discards the Facebook window, <code>result.isCancelled</code> is only captured on iOS.  <code>result.postId</code> isn't populated on either iOS and Android.</p>
  
  <p>Is there something that needs to be done in order for <code>result.isCancelled</code> to be populated on Android and/or <code>result.postId</code> to be populated on either platform?</p>
  
  <pre><code>  ShareDialog.canShow(shareContent).then(
      (canShow) =&gt; {
        if (canShow) {
          return ShareDialog.show(shareContent);
        } else {
          return false;
        }
      },
    ).then(
      (result) =&gt; {
        if (!result) {
          Alert.alert('Error', 'You must have Facebook installed on this device in order to share this post')
        } else if (result.isCancelled) {
          Alert.alert('Cancelled', 'Share cancelled');
        } else {
          Alert.alert('Success!', 'Share successful');
        }
      },
      (error) =&gt; {
        Alert.alert(`Share fail with error: ${error}`);
      },
    )
  </code></pre>