This commit improves in-app feature flags to persist what is currently only
stored in a Reagent atom by using RN Async Storage
https://reactnative.dev/docs/asyncstorage. This should make them more convenient
to use, which is a good thing overall for developers.
Additionally, there's now a top-right button in screen Settings > Feature Flags
that will reset the flags to the initial values obtained from environment
variables.
These in-app feature flags are exclusively available in debug builds in
Settings > Feature Flags, and only visible when flag ENABLE_QUO_PREVIEW is
enabled. There's no impact whatsoever in prod builds. A reminder that they are
not meant to be used by users (yet).
It's worth noting that RN has deprecated Async Storage and now recommends other
community solutions, but for a dev-only feature, I think it's fine.
8ad58bb364