- Uses Xamarin.Essentials in osu.Game.PlayerLoader to check battery level
- Encapsulated battery checking in the public BatteryManager class so battery level and plugged in status can be accessed and edited in TestPlayerLoader
- When checking battery level, catch NotImplementedException thrown by Xamarin.Essentials.Battery on non-mobile platforms
- Added visual unit tests for battery notification
To mock battery status and level, we had to define a batteryManager object in TestPlayerLoader and add a new function ResetPlayerWithBattery()
Co-Authored-By: Marlina José <marlina@umich.edu>