feat(ios): add onBandwidthUpdate event (#3331)

* feat(ios): add onBandwidthUpdate event

docs/pages/component/events.md

@@ -86,14 +86,27 @@ Payload:
 Property | Type | Description
 --- | --- | ---
 bitrate | number | The estimated bitrate in bits/sec
+width | number | The width of the video (android only)
+height | number | The height of the video (android only)
+trackId | string | The track ID of the video track (android only)
 
-Example:
+Example on iOS:
 ```javascript
 {
   bitrate: 1000000
 }
 ```
 
+Example on Android:
+```javascript
+{
+  bitrate: 1000000
+  width: 1920
+  height: 1080
+  trackId: 'some-track-id'
+}
+```
+
 Note: On Android, you must set the [reportBandwidth](#reportbandwidth) prop to enable this event. This is due to the high volume of events generated.
 
 Platforms: Android