Enable the 'Add stage and group labels based on team labels' policy for open MRs from now on

Consider adding documentation to the handbook pages for Triage Operations when creating a new triage policy or triage package:

• https://gitlab.com/gitlab-com/www-gitlab-com/blob/master/source/handbook/engineering/quality/guidelines/triage-operations/index.html.md

Closes #215 (closed)