Enable tracking unique visits by default

Add changelog

app/helpers/analytics/unique_visits_helper.rb

@@ -14,7 +14,7 @@ module Analytics
     end
 
     def track_visit(target_id)
-      return unless Feature.enabled?(:track_unique_visits)
+      return unless Feature.enabled?(:track_unique_visits, default_enabled: true)
       return unless visitor_id
 
       Gitlab::Analytics::UniqueVisits.new.track_visit(visitor_id, target_id)

changelogs/unreleased/enable-track-unique-visits-ff-by-default.yml

+---
+title: Enable track_unique_visits feature flag by default
+merge_request: 43989
+author:
+type: other

config/feature_flags/development/track_unique_visits.yml

@@ -4,4 +4,4 @@ introduced_by_url: https://gitlab.com/gitlab-org/gitlab/-/merge_requests/33146
 rollout_issue_url: 
 group: group::analytics
 type: development
-default_enabled: false
+default_enabled: true