Fix inconsistency in ArchivedFile::getUser

It was returning user id, where the interface is to take an
argument, and by default return the user text.

This caused weird output (user id instead of name) in certain places.

Change-Id: Icae281de67cfaafe52f1fb1fa4c7556aff7cd306
Follow-up: 8bd386e3680808d1ae1166140ef6917f0498ef3a
Merge "Fix inconsistency in ArchivedFile::getUser"