Removed Value property coercion in RadioButton (#32489)

Eliminated the coercion logic that set RadioButton.Value to the instance when null, allowing Value to be explicitly set to null. Updated related unit test to reflect the new behavior.

Author: kubaflo

src/Controls/src/Core/RadioButton/RadioButton.cs

@@ -56,8 +56,7 @@ public partial class RadioButton : TemplatedView, IElementConfiguration<RadioBut
 		/// <summary>Bindable property for <see cref="Value"/>.</summary>
 		public static readonly BindableProperty ValueProperty =
 			BindableProperty.Create(nameof(Value), typeof(object), typeof(RadioButton), null,
-			propertyChanged: (b, o, n) => ((RadioButton)b).OnValuePropertyChanged(),
-			coerceValue: (b, o) => o ?? b);
+			propertyChanged: (b, o, n) => ((RadioButton)b).OnValuePropertyChanged());
 
 		/// <summary>Bindable property for <see cref="IsChecked"/>.</summary>
 		public static readonly BindableProperty IsCheckedProperty = BindableProperty.Create(
@@ -210,9 +209,6 @@ public RadioButton()
 		{
 			_platformConfigurationRegistry = new Lazy<PlatformConfigurationRegistry<RadioButton>>(() =>
 				new PlatformConfigurationRegistry<RadioButton>(this));
-
-			//initialize Value to prevent null value
-			Value = this;
 		}
 
 		/// <inheritdoc/>

src/Controls/tests/Core.UnitTests/RadioButtonTests.cs

@@ -305,15 +305,19 @@ public void GroupNullSelectionClearsAnySelection()
 		}
 
 		[Fact]
-		public void ValuePropertyCoercedToItselfIfSetToNull()
+		public void ValuePropertyCanBeSetToNull()
 		{
 			var radioButton = new RadioButton();
 
-			Assert.Equal(radioButton, radioButton.Value);
+			Assert.Null(radioButton.Value);
+
+			radioButton.Value = 1;
+
+			Assert.Equal(1, radioButton.Value);
 
 			radioButton.Value = null;
 
-			Assert.Equal(radioButton, radioButton.Value);
+			Assert.Null(radioButton.Value);
 		}
 	}
 }