Removed android popup implementation since it was broken anyway

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

@@ -1,112 +0,0 @@
-using System;
-using Android.Content;
-using Android.Graphics;
-using Android.Runtime;
-using Android.Views;
-using Avalonia.Controls;
-using Avalonia.Platform;
-
-namespace Avalonia.Android.Platform.SkiaPlatform
-{
-    class PopupImpl : TopLevelImpl, IPopupImpl
-    {
-        private PixelPoint _position;
-        private bool _isAdded;
-        Action IWindowBaseImpl.Activated { get; set; }
-        public Action<PixelPoint> PositionChanged { get; set; }
-        public Action Deactivated { get; set; }
-
-        public PopupImpl() : base(ActivityTracker.Current, true)
-        {
-        }
-
-        private Size _clientSize = new Size(1, 1);
-
-        public void Resize(Size value)
-        {
-            if (View == null)
-                return;
-            _clientSize = value;
-            UpdateParams();
-        }
-
-        public void SetMinMaxSize(Size minSize, Size maxSize)
-        {
-        }
-
-        public IScreenImpl Screen { get; }
-
-        public PixelPoint Position
-        {
-            get { return _position; }
-            set
-            {
-                _position = value;
-                PositionChanged?.Invoke(_position);
-                UpdateParams();
-            }
-        }
-
-        WindowManagerLayoutParams CreateParams() => new WindowManagerLayoutParams(0,
-            WindowManagerFlags.NotTouchModal, Format.Translucent)
-        {
-            Gravity = GravityFlags.Left | GravityFlags.Top,
-            WindowAnimations = 0,
-            X = (int) _position.X,
-            Y = (int) _position.Y,
-            Width = Math.Max(1, (int) _clientSize.Width),
-            Height = Math.Max(1, (int) _clientSize.Height)
-        };
-
-        void UpdateParams()
-        {
-            if (_isAdded)
-                ActivityTracker.Current?.WindowManager?.UpdateViewLayout(View, CreateParams());
-        }
-
-        public override void Show()
-        {
-            if (_isAdded)
-                return;
-            ActivityTracker.Current.WindowManager.AddView(View, CreateParams());
-            _isAdded = true;
-        }
-
-        public override void Hide()
-        {
-            if (_isAdded)
-            {
-                var wm = View.Context.ApplicationContext.GetSystemService(Context.WindowService)
-                    .JavaCast<IWindowManager>();
-                wm.RemoveView(View);
-                _isAdded = false;
-            }
-        }
-
-        public override void Dispose()
-        {
-            Hide();
-            base.Dispose();
-        }
-
-
-        public void Activate()
-        {
-        }
-
-        public void BeginMoveDrag()
-        {
-            //Not supported
-        }
-
-        public void BeginResizeDrag(WindowEdge edge)
-        {
-            //Not supported
-        }
-
-        public void SetTopmost(bool value)
-        {
-            //Not supported
-        }
-    }
-}