[notifications: 2.0.1] Error while running the example

I tried to run the example on this [page](https://pub.dev/packages/notifications/example) but for some reason I am getting an error.
The error is-
`

════════ Exception caught by services library ══════════════════════════════════
MissingPluginException(No implementation found for method cancel on channel notifications)
════════════════════════════════════════════════════════════════════════════════
`
I also added the necessary permissions in the AndroidManifest.xml file but I am attaching the file, just in case I have not added the permissions correctly.
Kindly help.
[androidmanifest.xml](https://github.com/cph-cachet/flutter-plugins/files/8478390/androidmanifest.xml.txt)