Broken Sample: Custom Flyout in v11

[stevemonaco]

The Custom Flyout sample has a few issues.

• CreatePresenter no longer exists on FlyoutBase (it is part of PopupFlyoutBase)
• [!Image.SourceProperty] = this[!ImageProperty]: this line doesn't compile. Image is both a class property and type. The compiler picks the property instead of the Image type.
• The title is "How to Create a Custom Panel" instead of Flyout