update target SDK version: from 30 (Android 11) to 33 (Android 13)
changes:
* Android 10+: add foreground service type
* Android 11+: add permission to access all files
* Android 12+: add mutability flag to pending intent in notification
* Android 12+: show foreground service notification without 10s delay
* Android 12+: remove content from collapsed state of notification
- height restrictions for custom notifications on Android 12+:
* 48dp: collapsed state
* 88dp: heads up
* 252dp: expanded state
- height of custom notification:
* 64dp
* Android 13+: add runtime permission to show foreground service notification
* update build tools
see:
* https://developer.android.com/about/versions/10/features#fg-service-types
https://developer.android.com/reference/android/R.attr#foregroundServiceType
* https://developer.android.com/about/versions/11/privacy/storage#permissions
https://developer.android.com/about/versions/11/privacy/storage#all-files-access
* https://developer.android.com/about/versions/12/behavior-changes-12#pending-intent-mutability
* https://developer.android.com/about/versions/12/behavior-changes-all#foreground-service-notification-delay
https://developer.android.com/guide/components/foreground-services#notification-immediate
* https://developer.android.com/about/versions/12/behavior-changes-12#custom-notifications
https://developer.android.com/develop/ui/views/notifications/custom-notification
* https://developer.android.com/about/versions/13/behavior-changes-13#notification-permission-fgs-appearance
https://developer.android.com/develop/ui/views/notifications/notification-permission
