Make sure all specs run properly

What does this MR do?

In https://gitlab.com/gitlab-org/gitlab-ce/merge_requests/30096 we introduced new description field for Issue trackers and made sure GitLab is able to read from both title and description fields but also from properties where we have old data.

That has been made using before_save callback which takes data from properties and moves them into the db fields.

We also tried to make sure reading works for both cases - when data are stored in properties and when data are stored in the fields.

However, during creating tests records, we don't skip callbacks - that means during creating the records only the "new" state (data in title & description fields) was created.

This MR makes sure that legacy data are handled well by creating them correctly without the before_save callback.

Does this MR meet the acceptance criteria?

Conformity

• [-] Changelog entry
• [-] Documentation created/updated or follow-up review issue created
• Code review guidelines
• Merge request performance guidelines
• Style guides
• [-] Database guides
• [-] Separation of EE specific content

Performance and testing

• Review and add/update tests for this feature/bug. Consider all test levels. See the Test Planning Process.
• [-] Tested in all supported browsers

Security

If this MR contains changes to processing or storing of credentials or tokens, authorization and authentication methods and other items described in the security review guidelines:

• [-] Label as security and @ mention @gitlab-com/gl-security/appsec
• [-] The MR includes necessary changes to maintain consistency between UI, API, email, or other methods
• [-] Security reports checked/validated by a reviewer from the AppSec team