INTEG-307: [integ-ecms] Status of document isn't updated in the Activity when passing it manually to "Draft"

Problem analysis:
* When the publication state is changed manually to "draft" without any content update, no event is fired.
  As a consequence, the new state isn't updated in Content Activity.

Fix description:
* When rendering a Content Activity, get the publication state directly from WCMPublicationService.getContentState() instead from Activity itself.