User phone is not persisted to database after trial registering

Upstream MR

Summary

The phone number is not saved into database while the user registration is succeed in this flow, which is missed out in the real name system issue #157

Steps to reproduce

1. Goto https://jihulab.com/-/trial_registrations/new.
2. Complete the registration process.
3. Check the Database.

What is the current bug behavior?

The telephone number is not existed in DB.

What is the expected correct behavior?

The telephone number can be saved to DB.

Screenshot