[AuthUI] User settings cannot fill in phone number and username if primary login method is email

## Environment
- Server: Staging
- App: qa-authflow (Email + Password)
- Tested user agent:
- Web portal - Sign up your first user
- Android Flutter demo app - Open Settings
- Browser: Chrome on Mac
- Device: Samsung Galaxy A71 (Android 13)

## Description
If the project primary login is Email, after sign up, if user clicks to prompt the pre-built user setting page, and enter to edit profile, there will be phone number and username field, but user cannot edit them as they are for primary logins.

The same issue occurs on email field if the primary login is Phone.

## Steps to reproduce
1. Setup a project with Email + Password (with new authflow enabled)
2. Signup new user
3. Click "Open Settings"
4. Click edit profile icon on settings
6. Try to edit the phone number / username field, not sure what the fields mean and found that they are not editable

## Expected result

If the config does not support using that method to login, it should either hide the field in user profile, or still show but as a user profile info only which is not for login.

Also the word "Primary phone number" is confusing to user as there is also no secondary, and not sure what "primary" refers to in this field.

## Screenshot

Start by reproducing the issue in the pre-built user settings page with Email + Password, then inspect how profile fields are rendered when email or phone is the primary login method. Decide and apply the supported behavior for the inactive login field, and verify both email-primary and phone-primary configurations, including the confusing "Primary phone number" label.

Written by the indexing model from the issue text.