The Developer Preview for Android 11 is now available; test it out and share your feedback.

androidx.media.app

Classes

NotificationCompat Class containing media specfic styles that you can use with NotificationCompat.Builder.setStyle(NotificationCompat.Style)
NotificationCompat.DecoratedMediaCustomViewStyle Notification style for media custom views that are decorated by the system. 
NotificationCompat.MediaStyle Notification style for media playback notifications.