[BUG] PopupV2 background overlay remains visible after popup is closed through navigation

### Is there an existing issue for this?

- [x] I have searched the existing issues

### Did you read the "Reporting a bug" section on Contributing file?

- [x] I have read the "Reporting a bug" section on Contributing file: https://github.com/CommunityToolkit/Maui/blob/main/CONTRIBUTING.md#reporting-a-bug

### Current Behavior

In some cases on Android, I noticed that the popup's background overlay wouldn't always hide along with its popup when navigating between pages, **blocking the entire application, CanBeDismissedByTappingOutsideOfPopup does not matter**.

iOS has not been tested yet at the moment.

The simplest case is to call PopToRootAsync 1 frame after calling ShowPopup, the popup's background overlay will stay on top forever.

```
private void OnClicked(object? sender, EventArgs e)
{
Dispatcher.DispatchAsync(async () =>
{
// Be sure to specify the background color to see the overlay.
var options = new PopupOptions()
{
PageOverlayColor = Colors.Green
};

// It doesn't matter what to show.
var view = new Label
{
Text = "Tap to dismiss this popup",
BackgroundColor = Colors.Red
};

// 1. Show the popup without waiting for it to close
Shell.Current.ShowPopup(view, options);

// 2. Wait for 1 frame.
await Task.Yield();

// 3. Finally, pop to root. The animated flag does not matter.
await Shell.Current.Navigation.PopToRootAsync(false);

/*
* Now the popup itself is gone, but we see it's green overlay.
* The model stack is empty! Optionaly we can navigate to another page
* in the regular navigation stack and see that the page has changed
* under overlay. Essentially, the app is frozen and won't respond to touch.
*/
await Shell.Current.Navigation.PushAsync(new Page1());
});
}
```

### Expected Behavior

The overlay hides along with its popup, thereby not blocking the application.

### Steps To Reproduce

1. Open and debug on Android sample app: https://github.com/Bamich/popup-v2-overlay-bug
2. Click the button

### Link to public reproduction project repository

https://github.com/Bamich/popup-v2-overlay-bug

### Environment

```markdown
- .NET MAUI CommunityToolkit: 12.2.0
- .NET MAUI: 9.0.120
- OS: Android, API 33
```

### Actual behaviour

https://github.com/user-attachments/assets/c78b2b9f-0934-44b4-b6c8-48ee6243be26

### Expected behaviour

https://github.com/user-attachments/assets/37885a70-a5f8-4ec7-9911-553d820bab97

Run the linked popup-v2-overlay-bug reproduction on Android and follow the sequence through Shell.Current.ShowPopup, Task.Yield, and Navigation.PopToRootAsync. Compare the popup and overlay lifecycle during navigation; done means the overlay is removed with the popup and the app remains responsive after navigating.

Written by the indexing model from the issue text.