Document about bindings order on Android
## 🏗 Enhancement Proposal

[This](https://github.com/MvvmCross/MvvmCross/issues/729) issue desribes important peculiarity of working android bindings. I think it should be documented somewhere or fixed

### Pitch

It will help all users who meet the same problem quick fix their apps

### Platforms affected (mark all that apply)
- [ ] :iphone: iOS
- [x] :robot: Android
- [ ] :checkered_flag: WPF
- [ ] :earth_americas: UWP
- [ ] :apple: MacOS
- [ ] :tv: tvOS
- [ ] :monkey: Xamarin.Forms
