update exoplayer to 2.14.0 #40

investigate PlayerNotificationManager
- https://medium.com/google-exoplayer/playback-notifications-with-exoplayer-a2f1a18cf93b
- https://exoplayer.dev/doc/reference/com/google/android/exoplayer2/ui/PlayerNotificationManager.html

For the time being teapod will not sow a media notification as other streaming apps and media players don't show one either. Below is working prototype code for notifications using the PlayerNotificationManager.

 var playerNotificationManager = PlayerNotificationManager
     .Builder(application, 1, "player", DescriptionAdapter()).build()

// Create the NotificationChannel
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.O) {
     val name = "Test Name"
     val descriptionText = "Test Description2"
     val importance = NotificationManager.IMPORTANCE_LOW
     val mChannel = NotificationChannel("player", name, importance)
     mChannel.description = descriptionText
     // Register the channel with the system; you can't change the importance
     // or other notification behaviors after this
     val notificationManager = application
         .getSystemService(NOTIFICATION_SERVICE) as NotificationManager
     notificationManager.createNotificationChannel(mChannel)
}

playerNotificationManager.setMediaSessionToken(mediaSession.sessionToken)
playerNotificationManager.setPlayer(player)