Move methods back to original order.

Moving them like this was confusing the diff.

src/Avalonia.Controls/Button.cs

@@ -307,6 +307,11 @@ namespace Avalonia.Controls
             }
         }
         
+        protected override void OnPointerCaptureLost(PointerCaptureLostEventArgs e)
+        {
+            IsPressed = false;
+        }
+
         protected override void UpdateDataValidation<T>(AvaloniaProperty<T> property, BindingValue<T> value)
         {
             base.UpdateDataValidation(property, value);
@@ -323,11 +328,6 @@ namespace Avalonia.Controls
             }
         }
 
-        protected override void OnPointerCaptureLost(PointerCaptureLostEventArgs e)
-        {
-            IsPressed = false;
-        }
-
         /// <summary>
         /// Called when the <see cref="Command"/> property changes.
         /// </summary>