`permission_handler_android` Fix missing POST_NOTIFICATION permission in android manifest for example projects.

[dius00]

✨ What kind of change does this PR introduce? (Bug fix, feature, docs update...) Bug Fix in the example project, for the main package and android. Solves the following issue https://github.com/Baseflow/flutter-permission-handler/issues/865 for permission_handler_android

⤵️ What is the current behavior? Permission for notification are not requested on devices running Android 13 when running the example project in

permission_handler_android

🆕 What is the new behavior (if this is a feature change)? Permission for notification is requested as expected

💥 Does this PR introduce a breaking change? No.

🐛 Recommendations for testing Run the example project and verify that notification permission is requested on emulator/device running SDK 33

📝 Links to relevant issues/docs https://github.com/Baseflow/flutter-permission-handler/issues/865

🤔 Checklist before submitting

• [X] I made sure all projects build. - Will build when the changes in permission_handler_android are released
• [X] I updated pubspec.yaml with an appropriate new version according to the pub versioning philosophy.
• [X] I updated CHANGELOG.md to add a description of the change.
• [X] I followed the style guide lines (code style guide).
• [X] I updated the relevant documentation.
• [X] I rebased onto current master.