MediaItemChanged event is triggered every time a single media item is played

## 🔙 Regression

### Old (and correct) behavior

When playing a single media Item for the first time from a collection or from a single URL the event should not fire as there is no change in Media Item, and it did not fire in the previous version (1.0.7) which is normal.

### Current behavior

MediaItemChanged event is fired every time a media item is played for the first time, even though there is only one item to play

### Reproduction steps
- Add event handler CrossMediaManager.Current.MediaItemChanged += Current_MediaItemChanged;
- use Current.Play(url here)

### Configuration
Xamarin forms 5.0, vs 2019
**Version:** 1.0.8

**Platform:**

- [ ] :monkey: Xamarin.Forms

No source files or tests are named. Start by reproducing the issue with CrossMediaManager.Current.MediaItemChanged and Current.Play(url) on version 1.0.8, then compare the event behavior with version 1.0.7; done means the event does not fire when first playing the only media item.

Written by the indexing model from the issue text.