[FLI-988] Kotlin SDK

[markphelps]

Language

Kotlin

FFI Support

• I've validated that the language supports Foreign Function Interface (FFI) bindings

Additional Context

Since the client-side evaluation SDKs are particularly useful for mobile usecases, I think it makes sense to start working on some mobile-specific languages such as Swift, Kotlin (Android), and Flutter (#32)

@GeorgeMac turned me on to https://mozilla.github.io/uniffi-rs/Overview.html which looks to be able to generate FFI bindings in host languages such as Swift and Kotlin and is used by the Mozilla team for their mobile Firefox browsers

It would be great if we could get an implementation of flipt-client-kotlin which could use these bindings to call our existing flipt-engine-ffi library.

Willing to Implement

• I'm willing to help implement the Flipt Client SDK in this language if it's accepted. 🙌

Willing to Review

• I'm willing to review contributions to the Flipt Client SDK in this language if it's accepted.

Additional Notes

I can help with generating the bindings, creating the releases, setting up tests, etc, however, I will need help with the Kotlin wrapper code so that it is idiomatic Kotlin

_FLI-988