Native service for an in-app review to display on Android, using the new v1.8 Play Core Library binding for Xamarin

InAppReviewService.cs

[assembly: Xamarin.Forms.Dependency(typeof(NAMESPACE.Droid.InAppReviewService))]
namespace NAMESPACE.Droid
{
    public class InAppReviewService : IInAppReview
    {
        public void LaunchReview()
        {
#if DEBUG
            // FakeReviewManager does not interact with the Play Store, so no UI is shown
            // and no review is performed. Useful for unit tests.
            var manager = new FakeReviewManager(MainActivity.GlobalContext);
#else         
            var manager = ReviewManagerFactory.Create(MainActivity.GlobalContext);
#endif            
            var request = manager.RequestReviewFlow();
            request.AddOnCompleteListener(new OnCompleteListener(manager));
        }
    }
    
    public class OnCompleteListener : Java.Lang.Object, IOnCompleteListener
    {
        FakeReviewManager _fakeReviewManager;
        IReviewManager _reviewManager;
        bool _usesFakeManager;
        void IOnCompleteListener.OnComplete(Com.Google.Android.Play.Core.Tasks.Task p0)
        {
            if (!p0.IsSuccessful)
                return;
            // Canceling the review raises an exception which needs to be handled
            try
            {
                LaunchReview(p0);
            }
            catch(Exception ex)
            {
                Console.WriteLine(ex.Message);
            }
        }
        
        private void LaunchReview(Task p0)
        {        
            {
                var review = p0.GetResult(Java.Lang.Class.FromType(typeof(ReviewInfo)));
                if (_usesFakeManager)
                {
                    var x = _fakeReviewManager.LaunchReviewFlow(MainActivity.GlobalContext, (ReviewInfo)review);
                    x.AddOnCompleteListener(new OnCompleteListener(_fakeReviewManager));
                }
                else
                {
                    var x = _reviewManager.LaunchReviewFlow(MainActivity.GlobalContext, (ReviewInfo)review);
                    x.AddOnCompleteListener(new OnCompleteListener(_reviewManager));
                }
            }
        }
        
        public OnCompleteListener(FakeReviewManager fakeReviewManager)
        {
            _fakeReviewManager = fakeReviewManager;
            _usesFakeManager = true;
        }
        public OnCompleteListener(IReviewManager reviewManager)
        {
            _reviewManager = reviewManager;
        }
    }
}