Added failing test possibly for #3466.

Not sure if this is the cause of #3466, but it's definitely wrong.

tests/Avalonia.Base.UnitTests/AvaloniaObjectTests_SetValue.cs

@@ -240,6 +240,17 @@ namespace Avalonia.Base.UnitTests
             Assert.Equal("two", target.GetValue(Class1.FooProperty));
         }
 
+        [Fact]
+        public void SetValue_Animation_Overrides_LocalValue()
+        {
+            Class1 target = new Class1();
+
+            target.SetValue(Class1.FooProperty, "one", BindingPriority.LocalValue);
+            Assert.Equal("one", target.GetValue(Class1.FooProperty));
+            target.SetValue(Class1.FooProperty, "two", BindingPriority.Animation);
+            Assert.Equal("two", target.GetValue(Class1.FooProperty));
+        }
+
         [Fact]
         public void Setting_UnsetValue_Reverts_To_Default_Value()
         {