The View File Macro does not render attachments with multibyte filenames

Steps to reproduce

Download the two attachments:

1. 1450773_English-named_Files_Download_test.txt
2. 1450774_Korean-named_Files_Download_test_한글파일.txt

Attach both files to a Confluence page. Upon saving and subsequent edits, the korean file name will be rendered as "unknown attachment"

Testing Notes

1. The file can be downloaded through the Attachments screen
2. The file can be linked to as a link (Insert » Link » Files)
3. The file name displays correctly everywhere else