Add Distribution groups EM, staff and QA

What does this MR do and why?

Describe in detail what your merge request does and why.

This MR updates policy file to assign distribution report to Distribution:Deploy EM, and also mention Distribution group staff and QA.

@WarheadsSE @niskhakova - I included you two as mentioning because I think it is valuable to get your inputs for this triage process.

Expected impact & dry-runs

These are strongly recommended to assist reviewers and reduce the time to merge your change.

See https://gitlab.com/gitlab-org/quality/triage-ops/-/tree/master/doc/scheduled#testing-with-a-dry-run on how to perform dry-runs.

Action items

• (If applicable) Add documentation to the handbook pages for Triage Operations =>
• (If applicable) Identify the affected groups and how to communicate to them:
  • /cc @person_or_group =>
  • Relevant Slack channels =>
  • Engineering week-in-review