Opt-in Push Notifications

Is there an existing issue for this?

• I have searched the existing issues

Berty product

Mobile app

Feature request

An opt-in system for push notifications is important for various privacy reasons.

Context

Exposing messages to 3rd parties like Apple and Google isn't the best idea for an encrypted chat app, and push notifications can end up doing that (not sure about Berty's implementation, but still...)

Possible implementation

Ask on account creation.