Add Exception Message when trying to use FlyoutPage with NonAppCompat

Stubs/Xamarin.Forms.Platform.cs

@@ -163,7 +163,11 @@ internal class _PageRenderer { }
 
 
 
-#if !__IOS__
+#if __ANDROID__
+	// current previewer doesn't work with appcompat so this renderer is here for the previewer only
+	// once previewer switches to appcompat then we can remove this
+	[RenderWith(typeof(FlyoutPageRendererNonAppCompat))]
+#elif !__IOS__
 	[RenderWith(typeof(FlyoutPageRenderer))]
 #else
 	[RenderWith (typeof (PhoneFlyoutPageRenderer))]

Xamarin.Forms.Platform.Android/AppCompat/FormsAppCompatActivity.cs

@@ -126,6 +126,10 @@ static void RegisterHandlers()
 			RegisterHandler(typeof(Picker), typeof(AppCompat.PickerRenderer), typeof(PickerRenderer));
 			RegisterHandler(typeof(CarouselPage), typeof(AppCompat.CarouselPageRenderer), typeof(CarouselPageRenderer));
 			RegisterHandler(typeof(CheckBox), typeof(CheckBoxRenderer), typeof(CheckBoxDesignerRenderer));
+			RegisterHandler(typeof(FlyoutPage), typeof(FlyoutPageRenderer), typeof(FlyoutPageRendererNonAppCompat));
+#pragma warning disable CS0618 // Type or member is obsolete
+			RegisterHandler(typeof(MasterDetailPage), typeof(MasterDetailPageRenderer), typeof(MasterDetailRenderer));
+#pragma warning restore CS0618 // Type or member is obsolete
 
 			if (Forms.Flags.Contains(Flags.UseLegacyRenderers))
 			{

Xamarin.Forms.Platform.Android/Renderers/FlyoutPageRendererNonAppCompat.cs

@@ -0,0 +1,20 @@
+using System;
+using System.Collections.Generic;
+using System.Text;
+using Android.Content;
+using AView = Android.Views.View;
+
+namespace Xamarin.Forms.Platform.Android
+{
+	sealed class FlyoutPageRendererNonAppCompat : PageRenderer
+	{
+		public FlyoutPageRendererNonAppCompat(Context context) : base(context)
+		{
+		}
+
+		protected override void OnElementChanged(ElementChangedEventArgs<Page> e)
+		{
+			throw new Exception("FlyoutPage only works with Theme.AppCompat theme (or descendant)");
+		}
+	}
+}