0001 use firebase analytics for product usage events

Use Firebase Analytics for Product Usage Events

The first third-party Analytics Provider for Product Usage Events will be Firebase Analytics because OnTime already depends on Firebase for core app and messaging behavior, making the provider review smaller than introducing a separate analytics vendor. This choice still requires privacy policy, Google Play Data Safety, retention, deletion, and opt-out behavior to be reviewed before release because Product Usage Events will be sent to an external analytics provider.