Show audit ui based on created date, not modified

Audits get modified for administrative reasons, not limited to marking
them as approved or migrating from an OTM1 instance.

Don't show modified date, it doesn't reflect the true history of the
object correctly. Show created date.
Merge pull request #1560 from steventlamb/topic/fix_sidebar_audit_ui

Show audit ui based on created date, not modified