Implement multi-platform Preferences

[maximbircu]

Abstract

We need to implement a multiplatform Preferences mechanism to be able to persist configuration values on both iOS and Android.

Requirements

Implement multiplatform Preferences and use it as a dev tool configuration store.

Consumer flow

1. Open the sample app;
2. Notice a toggle tool on the screen; (Remember it's current state)
3. Update the toggle tool
4. Restart the app and make sure the configuration value was persisted and you don't see the old one.