PROD-909 Disable the registration page mapping on activity settings save

[surajkrsingh]

All Submissions:

• [x] Have you followed the Pull Requests Guidelines?
• [x] Does your code follow the WordPress' Coding Standards?
• [x] Have you checked to ensure there aren't other open Pull Requests for the same update/change?

Changes proposed in this Pull Request:

Fixes #1553 .

How to test the changes in this Pull Request:

1. Enable Registration from general settings
2. Move on the page settings and unset the Register Form page from the registration pages section
3. Move on the activity settings page and save it
4. Back on page settings and check the Register Form page option
5. The option will not auto-assign on the last save action

Proof Screenshots or Video

https://www.awesomescreenshot.com/video/5971551?key=4d3ef947971fe6b038d3f80c9c200e3a

Other information:

• [x] Have you added an explanation of what your changes do and why you'd like us to include them?
• [ ] Have you written new tests for your changes, as applicable?
• [x] Have you successfully run tests with your changes locally?

Changelog entry

Disable the registration page mapping on activity settings save action

[surajkrsingh]

@chetansatasiya Changes updated

Condition added for the term and policy pages also.