Add channel_id to job metadata for all content jobs.
Add channel_id to job metadata for all content jobs.

indirectlylit/kolibri,indirectlylit/kolibri,mrpau/kolibri,mrpau/kolibri,indirectlylit/kolibri,mrpau/kolibri,learningequality/kolibri,learningequality/kolibri,learningequality/kolibri,indirectlylit/kolibri,mrpau/kolibri,learningequality/kolibri