ActivityIndicator rendered as a ProgressRing in UWP

Currently ActivityIndicator is rendered as a ProgressBar in UWP (apparently this behavior is carried from WP 8 https://bugzilla.xamarin.com/show_bug.cgi?id=58651). This behavior makes the ActivityIndicator complicated to be used in many scenarios, as it is completely different in iOS and Android. If ProgressRing were used instead of ProgressBar to be rendered in UWP, the control would look much more homogeneous and it could be used in more scenarios.