[Android] Fix issue with BoxView Color and CornerRadius (#12069)

* Added repro sample

* Fix the issue

* Fixed build error

Xamarin.Forms.Controls.Issues/Xamarin.Forms.Controls.Issues.Shared/Issue12061.cs

@@ -0,0 +1,63 @@
+using Xamarin.Forms.Internals;
+using Xamarin.Forms.CustomAttributes;
+
+#if UITEST
+using Xamarin.UITest;
+using NUnit.Framework;
+using Xamarin.Forms.Core.UITests;
+#endif
+
+namespace Xamarin.Forms.Controls.Issues
+{
+#if UITEST
+	[Category(UITestCategories.BoxView)]
+#endif
+	[Preserve(AllMembers = true)]
+	[Issue(IssueTracker.Github, 12061,
+		"[Bug] [Android] BoxView color is cleared when updating corner radius",
+		PlatformAffected.Android)]
+	public class Issue12061 : TestContentPage
+	{
+		public Issue12061()
+		{
+		}
+
+		protected override void Init()
+		{
+			Title = "Issue 12061";
+
+			var layout = new StackLayout();
+
+			var instructions = new Label
+			{
+				Padding = 12,
+				BackgroundColor = Color.Black,
+				TextColor  = Color.White,
+				Text = "Tap the Button. The BoxView must be updated with ConerRadius but without losing the Color. If the BoxView Color is kept, the test has passed."
+			};
+
+			var boxView = new BoxView
+			{
+				CornerRadius = 0,
+				Color = Color.Red,
+				HeightRequest = 60
+			};
+
+			var button = new Button
+			{
+				Text = "Update CornerRadius"
+			};
+
+			layout.Children.Add(instructions);
+			layout.Children.Add(boxView);
+			layout.Children.Add(button);
+
+			Content = layout;
+
+			button.Clicked += (sender, args) =>
+			{
+				boxView.CornerRadius = 12;
+			};
+		}
+	}
+}

Xamarin.Forms.Controls.Issues/Xamarin.Forms.Controls.Issues.Shared/Xamarin.Forms.Controls.Issues.Shared.projitems

@@ -1732,6 +1732,7 @@
     </Compile>
     <Compile Include="$(MSBuildThisFileDirectory)Issue11869.cs" />
     <Compile Include="$(MSBuildThisFileDirectory)Issue11723.cs" />
+    <Compile Include="$(MSBuildThisFileDirectory)Issue12061.cs" />
     <Compile Include="$(MSBuildThisFileDirectory)Issue11155.cs" />
     <Compile Include="$(MSBuildThisFileDirectory)Issue11643.xaml.cs" />
     <Compile Include="$(MSBuildThisFileDirectory)HeaderFooterShellFlyout.cs" />

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

@@ -52,10 +52,8 @@ protected override void OnElementPropertyChanged(object sender, PropertyChangedE
 
 			base.OnElementPropertyChanged(sender, e);
 
-			if (e.IsOneOf(VisualElement.BackgroundColorProperty, VisualElement.BackgroundProperty, BoxView.ColorProperty))
+			if (e.IsOneOf(VisualElement.BackgroundColorProperty, VisualElement.BackgroundProperty, BoxView.ColorProperty, BoxView.CornerRadiusProperty))
 				UpdateBoxView();
-			else if (e.PropertyName == BoxView.CornerRadiusProperty.PropertyName)
-				UpdateCornerRadius();
 		}
 
 		protected override void UpdateBackgroundColor()
@@ -179,8 +177,6 @@ void UpdateCornerRadius()
 					backgroundGradient.SetCornerRadii(cornerRadii);
 				}
 			}
-
-			UpdateBackgroundColor();
 		}
 	}
 }