Fix: Spring Configuration for Google-Fit is broken

It appears that the previous way I'd hooked in it has not been working since mid-May.

It was already not set up in a great way, and unnecessarily using beans when we could just use @Value, but because it's broken we definitely need to fix it.

Additionally, we should ensure that the properties are referenced through kebab-case, as it is the recommended method in Spring Boot 2 projects.