fix issue with gids not being added for packages with shared user id

Squashed commit of the following:

commit 2bc4c29dab22d8a541dfca0a20320b307ba64cfb
Author: Suchi Amalapurapu <asuchitra@google.com>
Date:   Tue Aug 4 16:24:55 2009 -0700

    fix issue with gids not being added for packages with shared user id