Stubs for Android and iOS

src/Android/Avalonia.Android/Platform/SkiaPlatform/PopupImpl.cs

@@ -36,7 +36,11 @@ namespace Avalonia.Android.Platform.SkiaPlatform
             _clientSize = value;
             UpdateParams();
         }
-        
+
+        public void SetMinMaxSize(Size minSize, Size maxSize)
+        {
+        }
+
         public IScreenImpl Screen { get; }
 
         public Point Position

src/iOS/Avalonia.iOS/EmbeddableImpl.cs

@@ -14,6 +14,10 @@ namespace Avalonia.iOS
             
         }
 
+        public void SetMinMaxSize(Size minSize, Size maxSize)
+        {
+        }
+
         public IDisposable ShowDialog()
         {
             return Disposable.Empty;