We're stopping animations too soon and restarting animations too late on iOS during native view transitions.

On the way out, we stop the animator on the engine side right at viewWillDisappear. It's probably too early since the next view controller's transition animation still leaves the flutter view partly visible.

Probably easier fix, just defer the call for the right effect in the engine directly. Though it would still be nice to introduce a new AppLifecycleState for users to know (or reuse inactive?).

On the way back, we don't recreate a surface on the engine side or requests frames on the framework side until viewDidAppear when the transitions settled.

Would be nice to add a new AppLifecycleState for this as well. It's currently not handled or transmitted to the framework.

Send to framework and let the framework start requesting frame on new signal.