Enable instance_statistics feature flag by default

This change enables the `instance_statistics` feature flag by default.

app/controllers/admin/instance_statistics_controller.rb

@@ -13,6 +13,6 @@ class Admin::InstanceStatisticsController < Admin::ApplicationController
   end
 
   def check_feature_flag
-    render_404 unless Feature.enabled?(:instance_statistics)
+    render_404 unless Feature.enabled?(:instance_statistics, default_enabled: true)
   end
 end

app/views/layouts/nav/sidebar/_admin.html.haml

@@ -69,7 +69,7 @@
             = link_to admin_cohorts_path, title: _('Cohorts') do
               %span
                 = _('Cohorts')
-          - if Feature.enabled?(:instance_statistics)
+          - if Feature.enabled?(:instance_statistics, default_enabled: true)
             = nav_link(controller: :instance_statistics) do
               = link_to admin_instance_statistics_path, title: _('Instance Statistics') do
                 %span

changelogs/unreleased/enable_instance_statistics_ff_by_default.yml

+---
+title: Enable 'instance_statistics' feature flag by default
+merge_request: 46962
+author:
+type: changed

config/feature_flags/development/instance_statistics.yml

@@ -4,4 +4,4 @@ introduced_by_url: https://gitlab.com/gitlab-org/gitlab/-/merge_requests/40583
 rollout_issue_url: https://gitlab.com/gitlab-org/gitlab/-/issues/241711
 group: group::analytics
 type: development
-default_enabled: false
\ No newline at end of file
+default_enabled: true

doc/user/admin_area/analytics/instance_statistics.md

@@ -36,22 +36,3 @@ in the categories shown in [Total counts](#total-counts).
 These charts help you visualize how rapidly these records are being created on your instance.
 
 ![Instance Activity Pipelines chart](img/instance_activity_pipelines_chart_v13_6.png)
-
-### Enable or disable Instance Statistics
-
-Instance Statistics is under development and not ready for production use. It is
-deployed behind a feature flag that is **disabled by default**.
-[GitLab administrators with access to the GitLab Rails console](../../../administration/feature_flags.md)
-can enable it.
-
-To enable it:
-
-```ruby
-Feature.enable(:instance_statistics)
-```
-
-To disable it:
-
-```ruby
-Feature.disable(:instance_statistics)
-```