[ng-flutter] Update sample deps (angular 16) (#1784)

This PR updates the `ng-flutter` dependencies to use the latest Angular
version (16).

Closes: #1779
Closes: #1781
Closes: #1782
Closes: #1783

(The app seems to compile, build and deploy normally. [Deployed
here](https://dit-ng-flutter.web.app))

## Pre-launch Checklist

- [x] I read the [Flutter Style Guide] _recently_, and have followed its
advice.
- [x] I signed the [CLA].
- [x] I read the [Contributors Guide].
- [x] I updated/added relevant documentation (doc comments with `///`).
- [x] All existing and new tests are passing.

If you need help, consider asking for advice on the #hackers-devrel
channel on [Discord].

<!-- Links -->
[Flutter Style Guide]:
https://github.com/flutter/flutter/wiki/Style-guide-for-Flutter-repo
[CLA]: https://cla.developers.google.com/
[Discord]: https://github.com/flutter/flutter/wiki/Chat
[Contributors Guide]:
https://github.com/flutter/samples/blob/main/CONTRIBUTING.md