I can confirm this bug, although I don't use language-pack-gnome-zh-hans but language-pack-gnome-fr.
So everything is in french, including «Système», «Préférences» and «Administration».
But everything inside these 2 menus is in english ("About me", "Appearance",… "Computer janitor", "Disk utility"…).
The «Applications» menu also has some entries in english, like "Calculator" or "Rhythmbox Music Player".
I can confirm this bug, although I don't use language- pack-gnome- zh-hans but language- pack-gnome- fr.
So everything is in french, including «Système», «Préférences» and «Administration».
But everything inside these 2 menus is in english ("About me", "Appearance",… "Computer janitor", "Disk utility"…).
The «Applications» menu also has some entries in english, like "Calculator" or "Rhythmbox Music Player".