Rails 5: fix issue move service

What does this MR do?

For rails 5, attributes method returns the value instead of the database integer. Added bulk_insert_attributes that changes the enum value to an integer for bulk inserting.

Fixes spec/services/issues/move_service_spec.rb:126

see: https://gitlab.com/gitlab-org/gitlab-ce/-/jobs/95854619 and https://gitlab.com/gitlab-org/gitlab-ce/-/jobs/95855129.

What are the relevant issue numbers?

Does this MR meet the acceptance criteria?

• Changelog entry added, if necessary
• Documentation created/updated
• Tests added for this feature/bug
• Conforms to the code review guidelines
• Conforms to the merge request performance guidelines
• Conforms to the style guides
• Conforms to the database guides