A button renderer workaround for Samsung ripple problems

CustomButtonRenderer.cs

using System;
using Android.Content;
using Android.Content.Res;
using Android.Graphics.Drawables;
using MyProject.Droid.Renderers;
using Xamarin.Forms;
using Xamarin.Forms.Platform.Android;

[assembly: ExportRenderer(typeof(Button), typeof(CustomButtonRenderer))]
namespace MyProject.Droid.Renderers
{
	public class CustomButtonRenderer : ButtonRenderer
	{
		private GradientDrawable _normal, _pressed;

		public CustomButtonRenderer(Context context) : base(context)
		{
		}

		protected override void OnElementChanged(ElementChangedEventArgs<Button> e)
		{
			base.OnElementChanged(e);

			if (Control != null)
			{
				var density = Math.Max(1, Resources.DisplayMetrics.Density);
				var button = (Button)e.NewElement;
				var borderRadius = button.CornerRadius * density;
				var borderWidth = button.BorderWidth * density;

				// Create a drawable for the button's normal state
				_normal = new GradientDrawable();
				_normal.SetColor(button.BackgroundColor.ToAndroid());
				_normal.SetStroke((int)borderWidth, button.BorderColor.ToAndroid());
				_normal.SetCornerRadius(borderRadius);

				// Create a drawable for the button's pressed state
				_pressed = new GradientDrawable();

				var highlight = button.BackgroundColor.AddLuminosity(-0.05).ToAndroid();

				_pressed.SetColor(highlight);
				_pressed.SetStroke((int)borderWidth, button.BorderColor.ToAndroid());
				_pressed.SetCornerRadius(borderRadius);

				// Add the drawables to a state list and assign the state list to the button
				var sld = new StateListDrawable();
				sld.AddState(new int[] { Android.Resource.Attribute.StatePressed }, _pressed);
				sld.AddState(new int[] { }, _normal);

				Control.SetBackground(sld);
				Control.SetTextColor(Element.TextColor.ToAndroid());
			}
		}
	}
}

There is a Problem: if I change Button's BackgroundColor on runtime, this code would broke, not working then. XF: 4.8