Grid PopUp editor containment doesn't serialize

[StoyanGoranov]

Bug report

When a Grid is configured for PopUp Editing and the Containment property of the Window is configured it isn't serialized properly on the client-side.

Reproduction of the problem

1. Run this REPL
2. Start editing a row
3. Drag the PopUp outside of the visible area of the REPL

Current behavior

The editable.window configuration of the Grid gets serialized like this:

    "editable": {
            "mode": "popup",
            "window": {
                "scrollable": true,
                "content": null,
                "draggable": true,
                "title": "Edit"
            }
        }

despite the HtmlHelper configuration:

    .Editable(editable => editable.Mode(GridEditMode.InCell).Window(wind=>wind.Draggable(settings=>settings.Containment(".contain"))))

Expected/desired behavior

The configuration should serialize correctly.

Environment

• Kendo UI version: 2023.1.314