Request Form Not Translated Correctly in Customer Portal

Issue Summary

When a customer selects a different language than the system language used by JIRA, some system fields for example "summary", "attachments" are not translated.
though the description of some of these fields are correctly translated as seen in the image below:

Steps to Reproduce

1. Access JIRA Service Desk customer portal as a customer.
2. Change the profile language to German or other supported languages (System Language is set to English).
3. Save the change.
4. Attempt to create an issues in the customer portal.

Expected Behavior

JIRA would translate the issue fields to the language the customer selected.

Actual Behavior

JIRA Service Desk would show the fields in the language which JIRA is set to rather than the one selected by the customer.

Note:

• This functionality seems to have been addressed in JIRA Service Desk Cloud as seen here
• Changing the system language does not change this behavior.
• System fields would be expected to be translated if the language pack is bundled with Jira.
• Custom fields have an option to translate them at Jira Administration > issues > Custom fields, but this does not seem to be used by Service Desk.