Always Return New Version Feature Flags to Unleash Clients

What does this MR do?

Return new version feature flags to Unleash clients regardless of the state of the :feature_flags_new_version feature flag.

This is so that the new version flags can be toggled off and on without affecting the behavior of client application code where Unleash clients are consuming the Unleash flags from the server.

This could be useful if we have to disable the new version flags to rollback the feature.

Issue: #214684 (closed)

See: #214684 (comment 326429241)

Does this MR meet the acceptance criteria?

Conformity

• [-] Changelog entry
• Documentation (if required)
• Code review guidelines
• Merge request performance guidelines
• Style guides
• Database guides
• Separation of EE specific content

Availability 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
• Informed Infrastructure department of a default or new setting change, if applicable per definition of done

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