Video subtitles on chromecast

I use `exoplayer `with `exoplayer-cast-extension` in my android app. In the app its possible to play videos with subtitles (I have links on `.srt` files for each video source). And I want to cast these videos (on chromecast) with subtitles. For casting I use the following code:

```
castPlayer?.loadItem(MediaQueueItem.Builder(buildMediaInfo(videoUrl ?: "")).build(), 0L)

private fun buildMediaInfo(videoUrl: String): MediaInfo {
val movieMetadata = MediaMetadata(MediaMetadata.MEDIA_TYPE_MOVIE)
movieMetadata.putString(MediaMetadata.KEY_TITLE, getString(R.string.app_name))
return MediaInfo.Builder(videoUrl)
.setStreamType(MediaInfo.STREAM_TYPE_BUFFERED)
.setContentType("video/m3u8")
.setMetadata(movieMetadata)
.setStreamDuration(UNKNOWN_DURATION)
.build()
}
```

It plays video with chromecast well, but without subtitles. And I didnt find some method for adding subtitles for cast video. So, how to make them?