Roll packages to the ones published today.
Note that `native_assets_cli` was split up into `hooks` and
`code_assets`, and `native_assets_builder` was renamed to
`hooks_runner`.
Roll forward deps to the ones published today.
Note: `package:native_assets_cli` has a lower-bound on a Dart SDK dev
version to signal for which version of Dart and Flutter it is compatible
with. This means all these packages now have pre-release versions. Since
native assets is in experimental mode and not available on the
stable/beta branches, this is as expected.
Test exempt: Covered by existing tests, only rolling forward deps.
This PR is the dual of
https://dart-review.googlesource.com/c/sdk/+/420700 in the Dart SDK.
This PR adds support for user-defines for hooks in the root package
`pubspec.yaml`.
```yaml
hooks:
user_defines:
hook_user_defines: # package name
magic_value: 1000
```
For more design considerations see:
* https://github.com/dart-lang/native/issues/39
### Testing
This PR is covered by
`test/integration.shard/isolated/native_assets_test.dart`.
In this PR, we add a new test project
`dev/integration_tests/hook_user_defines/` and add a dependency on that
project in the mentioned test.
The integration test already covers `flutter run`, `flutter test`, and
`flutter build`.
