AnnotatedScrollBarLabel does not work with AOT

Describe the bug

Code using an AnnotatedScrollBar does not work with PublishAOT.

My page contains a <AnnotatedScrollBar Name="annotatedScrollBar" />. At runtime an exception will be thrown when something is added to the label collection.

Exception:

System.NotSupportedException: 'ICustomProperty support used by XAML binding for type 
'Microsoft.UI.Xaml.Controls.AnnotatedScrollBarLabel' (property 'Content') requires the type to marked with
'WinRT.GeneratedBindableCustomPropertyAttribute'. If this is a built-in type or a type that can't be marked, 
a wrapper type should be used around it that is marked to enable this support.'

Code snippet to add label:

annotatedScrollBar.Labels.Add(new AnnotatedScrollBarLabel("MyLabel", 200));

Labels is an IList<AnnotatedScrollBarLabel> and AnnotatedScrollBarLabel is sealed, so I think there is nothing I can do to make this work with AOT enabled.

Expected behavior

It should work, just like it does without AOT compilation.

NuGet package version

WinUI 3 - Windows App SDK 1.6.3: 1.6.241114003

Windows version

Windows 11 (24H2): Build 26100

Additional context

It works without AOT and the exception above is thrown with PublishAOT enabled.

Start by reproducing the exception with an AnnotatedScrollBar and AnnotatedScrollBarLabel in a Windows App SDK 1.6.3 app using PublishAOT, then inspect the AnnotatedScrollBarLabel Content binding and generated WinRT custom-property support. Done means adding a label works under AOT as it does without AOT, without the reported NotSupportedException.