* Don't call `PlatformViewCreatedCallback`s after `AndroidViewController` is disposed

Before this change it was possible that, if a `AndroidViewController` was disposed before we got the notification that the platform view was created, `PlatformViewCreatedCallback`s where called even after calling `AndroidViewController.dispose`.

Also makes `_PlatformViewLinkState._onPlatformViewCreated` more carful to only call `setState` when mounted.

Closes #84628
Closes #96384

* Allow all widgets to remove listeners from controller

* Remove assert

* Add expectations to test