Hybrid version for Xamarin and MAUI

[janwiebe-jump]

🏗 Enhancement Proposal

Get a Hybrid version of MediaManager to use with both Xamarin.Android / Xamarin.iOS projects and MAUI projects

Pitch

Existing Xamarin apps can use the latest Android 12 compatibility fixes in ExoPlayerXamarin, and work their way towards the upgrade to of their apps MAUI.

Possible approach:

1. Publish separate Nuget packages of ExoPlayerXamarin for Maui and for Xamarin.Android (based on this discussion.)
2. Add references to the packages based on the target framework (.net-xxx / mono-android-xxx)
3. Fix the build errors, possibly using some compile time constants

Alternative approach: Publish separate packages for MediaManagerMAUI and XamarinMediaManager, based on possibly separate branches

Platforms affected (mark all that apply)

• [X] :iphone: iOS
• [X] :robot: Android
• [ ] :checkered_flag: WPF
• [ ] :earth_americas: UWP
• [ ] :apple: MacOS
• [ ] :tv: tvOS
• [ ] :monkey: Xamarin.Forms