Add tracking and metrics to admin health check page

app/views/admin/health_check/show.html.haml

 - page_title _('Health Check')
 - no_errors = @errors.blank?
 
+#div{ data: { event_tracking_load: 'true', event_tracking: 'view_admin_health_check_pageload' } }
 %h1.page-title.gl-font-size-h-display= page_title
 = render Pajamas::AlertComponent.new(variant: :tip, dismissible: false, alert_options: { class: 'gl-mb-5' }) do |c|
   - c.with_body do

config/events/view_admin_health_check_pageload.yml

+---
+description: Tracks pageviews for the admin health check page
+internal_events: true
+action: view_admin_health_check_pageload
+identifiers:
+- user
+product_group: personal_productivity
+milestone: '17.2'
+introduced_by_url: https://gitlab.com/gitlab-org/gitlab/-/merge_requests/156829
+distributions:
+- ce
+- ee
+tiers:
+- free
+- premium
+- ultimate

config/metrics/counts_28d/count_distinct_user_id_from_view_admin_health_check_pageload_monthly.yml

+---
+key_path: redis_hll_counters.count_distinct_user_id_from_view_admin_health_check_pageload_monthly
+description: Monthly count of unique users who visited the admin health check page
+product_group: personal_productivity
+performance_indicator_type: []
+value_type: number
+status: active
+milestone: '17.2'
+introduced_by_url: https://gitlab.com/gitlab-org/gitlab/-/merge_requests/156829
+time_frame: 28d
+data_source: internal_events
+data_category: optional
+distribution:
+- ce
+- ee
+tier:
+- free
+- premium
+- ultimate
+events:
+- name: view_admin_health_check_pageload
+  unique: user.id

config/metrics/counts_28d/count_total_view_admin_health_check_pageload_monthly.yml

+---
+key_path: counts.count_total_view_admin_health_check_pageload_monthly
+description: Monthly count of total users who visited the admin health check page
+product_group: personal_productivity
+performance_indicator_type: []
+value_type: number
+status: active
+milestone: '17.2'
+introduced_by_url: https://gitlab.com/gitlab-org/gitlab/-/merge_requests/156829
+time_frame: 28d
+data_source: internal_events
+data_category: optional
+distribution:
+- ce
+- ee
+tier:
+- free
+- premium
+- ultimate
+events:
+- name: view_admin_health_check_pageload

config/metrics/counts_7d/count_distinct_user_id_from_view_admin_health_check_pageload_weekly.yml

+---
+key_path: redis_hll_counters.count_distinct_user_id_from_view_admin_health_check_pageload_weekly
+description: Weekly count of unique users who visited the admin health check page
+product_group: personal_productivity
+performance_indicator_type: []
+value_type: number
+status: active
+milestone: '17.2'
+introduced_by_url: https://gitlab.com/gitlab-org/gitlab/-/merge_requests/156829
+time_frame: 7d
+data_source: internal_events
+data_category: optional
+distribution:
+- ce
+- ee
+tier:
+- free
+- premium
+- ultimate
+events:
+- name: view_admin_health_check_pageload
+  unique: user.id

config/metrics/counts_7d/count_total_view_admin_health_check_pageload_weekly.yml

+---
+key_path: counts.count_total_view_admin_health_check_pageload_weekly
+description: Weekly count of total users who visited the admin health check page
+product_group: personal_productivity
+performance_indicator_type: []
+value_type: number
+status: active
+milestone: '17.2'
+introduced_by_url: https://gitlab.com/gitlab-org/gitlab/-/merge_requests/156829
+time_frame: 7d
+data_source: internal_events
+data_category: optional
+distribution:
+- ce
+- ee
+tier:
+- free
+- premium
+- ultimate
+events:
+- name: view_admin_health_check_pageload