Add redrawing of Snackbar and Toast when the screen is rotated

[cat0363]

This PR resolves the issue where when a long message that does not include a line feed code is specified for Snackbar and Toast, it is not drawn correctly after the screen is rotated.

Description of Change

Override the LayoutSubviews method of the RoundedView class that draws the Snackbar and Toast background and call the Draw method so that the Snackbar and Toast are redrawn after the screen is rotated.

[src\CommunityToolkit.Maui.Core\Views\RoundedView.macios.cs]

/// <inheritdoc />
public override void LayoutSubviews()
{
    base.LayoutSubviews();
    Draw(Frame);
}

This will cause Snackbar and Toast to be redrawn after the screen is rotated, so they will be drawn at the intended size.
This also resolves the issue where the corner shapes of Snackbar and Toast appear to have changed without being redrawn.

Linked Issues

• Fixes [BUG] Snackbar and Toast corner shape changes when screen is rotated on iOS #1404

PR Checklist

• Has a linked Issue, and the Issue has been approved(bug) or Championed (feature/proposal)
• Has tests (if omitted, state reason in description)
• Has samples (if omitted, state reason in description)
• Rebased on top of main at time of PR
• Changes adhere to coding standard
• Documentation created or updated: https://github.com/MicrosoftDocs/CommunityToolkit/pull/XYZ

Additional information

Below are the verification results after fix.

[Snackbar]

[Before Rotation]	[After Rotation]

[Toast]

[Before Rotation]	[After Rotation]

In both execution results, you can see that the Snackbar and Toast are drawn at the intended size after the screen is rotated.