Fix notification permissions in project.
After support for Provisional authorization was added to iOS, notifications no longer work in this project, because default ask is with provisional which is auto-granted and causes notifications to work silently.
With Android 13 we also have to support notification permission too.
This PR adds permission requesting in code for both platforms. While iOS could be set up in settings, I think it's better to do this in code to show how it's done on both platforms.
Fix notification permissions in project. After support for Provisional authorization was added to iOS, notifications no longer work in this project, because default ask is with provisional which is auto-granted and causes notifications to work silently. With Android 13 we also have to support notification permission too. This PR adds permission requesting in code for both platforms. While iOS could be set up in settings, I think it's better to do this in code to show how it's done on both platforms.