Deprecated version of the Android embedding throws warning

## 🏗 Enhancement Proposal

The plugins `contacts_plugin, permission_handler` use a deprecated version of the Android embedding.
To avoid unexpected runtime failures, or future build failures, try to see if these plugins support the Android V2 embedding. Otherwise, consider removing them since a future release of Flutter will remove these deprecated APIs.
If you are plugin author, take a look at the docs for migrating the plugin to the V2 embedding: https://flutter.dev/go/android-plugin-migration.

### Pitch

Fixing this issue will make the library to be updated with the current Android methodologies and prevent future issues that could be caused when the deprecated feature is eventually removed from Flutter.

### Platforms affected (mark all that apply)
- [ ] :iphone: iOS
- [x ] :robot: Android

Start by reading the Android plugin migration documentation linked in the issue, then inspect how contacts_plugin and permission_handler use the Android embedding. Done means the affected plugins no longer rely on the deprecated embedding and the warning described in the issue is resolved.

Written by the indexing model from the issue text.