consolekit: dep on glib-2.0-native

This is required for glib-gettextize. Discovered while testing for SB-1507.

Signed-off-by: Christopher Larson <kergoth@gmail.com>
consolekit: allow explicit enable/disable of polkit

JIRA: SB-1507

Signed-off-by: Christopher Larson <kergoth@gmail.com>