If the element's renderer has already been nulled or disposed, request zero space for it (#12114)

fixes #10801

Author: hartez

Xamarin.Forms.Platform.Android/Platform.cs

@@ -1335,9 +1335,13 @@ public static SizeRequest GetNativeSize(VisualElement view, double widthConstrai
 		{
 			Performance.Start(out string reference);
 
-			// FIXME: potential crash
 			IVisualElementRenderer visualElementRenderer = GetRenderer(view);
 
+			if (visualElementRenderer == null || visualElementRenderer.View.IsDisposed())
+			{
+				return new SizeRequest(Size.Zero, Size.Zero);
+			}
+
 			var context = visualElementRenderer.View.Context;
 
 			// negative numbers have special meanings to android they don't to us