rolled back the job api custom_file copy destination change

[yhwen]

Fixes # .

Description

Rolled back the job api custom_file copy destination change, Keep the custom file sub-folder structure.

Types of changes

• Non-breaking change (fix or new feature that would not break existing functionality).
• Breaking change (fix or new feature that would cause existing functionality to change).
• New tests added to cover the changes.
• Quick tests passed locally by running ./runtest.sh.
• In-line docstrings updated.
• Documentation updated.

[SYangster]

LGTM

[chesterxgchen]

/build