Fire Action PopupOptions.OnTappingOutsideOfPopup when Android Back Button Pressed

[TheCodeTraveler]

Description of Change

This PR updates the logic in PopupPage.OnBackButtonPressed to fire Action PopupOptions.OnTappingOutsideOfPopup and dismiss the Popup when CanBeDismissedByTappingOutsideOfPopup is true.

Linked Issues

• Fixes PopupV2 - OnTappingOutsideOfPopup not called in OnBackButtonPressed #2798

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/pulls

Additional information

Tp avoid duplicating code, this PR leverages the existing logic in ICommand tapOutsideOfPopupCommand

[Copilot]

Pull Request Overview

This PR updates the Android back button handling in PopupPage.OnBackButtonPressed so that tapping the back button now invokes the OnTappingOutsideOfPopup action and dismisses the popup when allowed.

• Switched the dismissal check from GetCanBeDismissedByTappingOutsideOfPopup to tapOutsideOfPopupCommand.CanExecute(null)
• Replaced the direct CloseAsync call with tapOutsideOfPopupCommand.Execute(null)
• Ensures the popup remains open by always returning true

Comments suppressed due to low confidence (1)

src/CommunityToolkit.Maui/Views/Popup/PopupPage.shared.cs:103

• Add unit tests to verify that OnBackButtonPressed correctly fires the OnTappingOutsideOfPopup action and dismisses the popup when CanBeDismissedByTappingOutsideOfPopup is true, and remains inert otherwise.

	protected override bool OnBackButtonPressed()

[bijington]

LGTM!