Xamarin Forms - Video cannot be played when AutoPlay is set to false on iOS

## 🐛 Bug Report

Using the VideoView in Xamarin forms, if you set autoplay to false, the video will stay black and never play. Tapping play does nothing at all. I've seen this with two urls so far.
### Expected behavior
Video should play when play is pressed or Play() method is called
### Reproduction steps
Here is my code to reproduce

> public partial class MainPage : ContentPage
{
public MainPage()
{
InitializeComponent();
var videoPlayer = new VideoView();
videoPlayer.Source = "https://commondatastorage.googleapis.com/gtv-videos-bucket/sample/BigBuckBunny.mp4";
videoPlayer.VerticalOptions = LayoutOptions.Center;
videoPlayer.HorizontalOptions = LayoutOptions.Center;
videoPlayer.WidthRequest = 200;
videoPlayer.HeightRequest = 200;
videoPlayer.ShowControls = true;
videoPlayer.AutoPlay = false;
Content = videoPlayer;
}
}

### Configuration

**Version:** v0.8.18
iOS 12.4
iPhone 6s
Xamarin Forms 4.3
Plugin.MediaManager: v0.8.18
Plugin.MediaManager.Forms: v0.8.18

**Platform:**
- [x] :iphone: iOS
- [ ] :robot: Android
- [ ] :checkered_flag: WPF
- [ ] :earth_americas: UWP
- [ ] :apple: MacOS
- [ ] :tv: tvOS
- [x] :monkey: Xamarin.Forms

Start by reproducing the provided MainPage example on iOS with AutoPlay set to false, using the reported Xamarin Forms and Plugin.MediaManager versions. Trace the VideoView playback path when the play control or Play() is invoked; done means the video displays and begins playback in both cases.

Written by the indexing model from the issue text.