DisplayAreaWatcher's updated event cannot be triggered

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### Describe the bug

`DisplayAreaWatcher.Updated` event can occur when the configuration of a `DisplayArea` has changed. If I understand it correctly, the change can include the work area's size changed when the display settings are changed or even when the taskbar is automatically hidden. However, no luck,

### Steps to reproduce the bug

For a simple project with a main window and a main page, add in an event like page_OnLoaded:

```C#
# windowId: WindowId object
var displayAreaWatcher = DisplayArea.CreateWatcher();
displayAreaWatcher .Updated += (watcher, args) =>
{
throw new NotImplementedException();
};
displayAreaWatcher .Start();
```

### Expected behavior

_No response_

### Screenshots

_No response_

### NuGet package version

Windows App SDK 1.2.1: 1.2.221116.1

### Packaging type

Packaged (MSIX)

### Windows version

Windows 11 version 22H2 (22621, 2022 Update)

### IDE

Visual Studio 2022

### Additional context

_No response_

Start with the DisplayArea.CreateWatcher entry point in a packaged Windows App SDK 1.2.1 app, using the page_OnLoaded reproduction on Windows 11 22H2. Trigger display-setting and automatic-taskbar-hiding changes and verify whether DisplayAreaWatcher.Updated fires; document the observed behavior and determine the relevant fix or limitation.

Written by the indexing model from the issue text.