[keyserver] Don't invalidate cookies for identity DDB population if codeVersion doesn't provide necessary info

Summary: Long commit title, but basically explains it all.

Test Plan: Actually run the cronjob on my local database, which has a good amount of data populated

Reviewers: varun, atul, jon

Reviewed By: varun

Subscribers: tomek

Differential Revision: https://phab.comm.dev/D7000