Non Admin CSV import doesn't import child value of cascade select list

Summary

Non-Admin CSV import doesn't import child value of cascade select list

Steps to Reproduce

1. Create a custom field of Type Select List (cascade)
2. Set an option like Parent value: USA, Child value: New York
3. Create a CSV to import cascade data following the docs like:

   Summary, My Cascading Custom Field
   Example Summary, USA -> New York
   

4. Go to Issues(Menu) > Import Issues from CSV
5. Import the CSV to a project with the cascade field

Expected Results

The issue should be created and the cascade field information should be successfully imported

Actual Results

The issue is created. However, only the parent value is added. The child value is not imported.

Notes

This works fine for Admin CSV import (Admin-menu>System>IMPORT AND EXPORT>External System Import)