MediaItem.extras should be Object?

[khensolomon]

Feature proposal

I wish that the MediaItem property extras should be Object?. So that we don't have to convert the data back and forth.

final Map<String, dynamic>? extras;

Motivating use case(s)

In my case of playlist, I have the need of the current playing MediaItem is notify in other music list, so user know what it is playing when browsing.

Also type Map<String, dynamic>? can be provided in Object?. I am thinking it is more flexible.

[ryanheise]

Extras must be a map because it corresponds to the Android API is is named after which is also a map.