Split Growth Weekly Report into Activation report and Acquisition report

What does this MR do and why?

Due to Growth being split into multiple teams we need to separate Growth Weekly Report which was previously shared across all Growth into two separate reports: Acquisition and Activation. This is a bit non-DRI solution which could be temporary if we find more teams interested in having this report, but for now I separated it into two distinct policy files.

Expected impact & dry-runs

Only impact is on Growth team's weekly report generation.

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-policies-with-a-dry-run on how to perform dry-runs for new policies.

See https://gitlab.com/gitlab-org/quality/triage-ops/-/blob/master/doc/reactive/best_practices.md#use-the-sandbox-to-test-new-processors on how to make sure a new processor can be tested.

Action items

• If adding environment variables for reactive processors, update config/triage-web.yaml and .gitlab/ci/triage-web.yml
• (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