Not Implemented crash

[steven-spiel]

We are using 0.1.3 and observed this crash coming from onDetachedFromActivity in OptimizelyPlugin.kt link to code

I didn't think a TODO would crash an app, but I thought I'd let you know about it.

[kevin49999]

Thanks for pointing this out @steven-spiel. It may make sense to change those to comments like in the example here: https://flutter.dev/docs/development/packages-and-plugins/plugin-api-migration or just remove them since I don't think we need to do any cleanup in these methods for this plugin