"New Version Available" check

Every time a user opens the app we should check if they're on the latest version on the Play Store. If they're not, we should show a dialog that tells them to update.

Ideally we'd have 2 flags on RemoteConfig:
- `android_check_update_available`
- `android_force_update` - if this is `true`, we should not let the user get past that screen until she's on the latest version.

Both flags will default to `true`.

Should look similar to the iOS implementation:

Texts:
EN
- title: App Update Available
- text: A new app version is available. Please update the app to use the latest features

RO
- title: Actualizare disponibilă
- text: O nouă versiune a aplicației este disponibilă. Te rugăm să faci update pentru a folosi cele mai recente funcționalități.

Start by reviewing the existing iOS implementation referenced in the issue and the Android app’s RemoteConfig and startup entry points. Verify the Play Store version check, the two default-true flags, the localized EN/RO dialog text, and the blocking behavior when force update is enabled; done means optional updates allow continuation and forced updates do not.

Written by the indexing model from the issue text.