Emit correct VideoEventType (flutter#2305)

[quick_actions] Add DartDoc and test coverage (flutter#2298)

Also adds a lint to prevent undocumented DartDocs from being added in
the future.

Some of the APIs were public when they really should have been
`@visibleForTesting` or even private. Added some `@visibleForTesting`
annotations as well.

[camera] Fix unawaited future errors (flutter#2312)

There's a over a dozen API surfaces that are undocumented still. This
just fixes one of the new pedantic lints.

[android_intent] Fix pedantic linter errors (flutter#2310)

[android_alarm_manager] Testing and documentation (flutter#2283)

* [android_alarm_manager] Testing and documentation

Unit tests the plugin, and adds a lint for missing DartDocs.

* Review feedback

- Wrap InstanceWrappers into a single `setTestOverride` method.
- Replace potentially garbage collected lambdas with top level
functions.

* Review feedback

[video_player] Improve DartDocs and test coverage (flutter#2286)

Also adds a lint to prevent undocumented APIs going forward.

[shared_preferences] Add missing DartDoc (flutter#2296)

Also adds a lint to prevent further undocumented methods.

[share] README update (flutter#2297)

Adds a little more info on how to use the plugin. Also adds linter
options to prevent any undocumented APIs from being added in the future.

[path_provider] Add v2 embedding support for (flutter#2284)

[image_picker]fix a crash when a non-image file is picked. (flutter#2293

)