Add last updated time to devops score page

This change the last updated time to devops score page.

app/presenters/dev_ops_report/metric_presenter.rb

@@ -2,6 +2,8 @@
 
 module DevOpsReport
   class MetricPresenter < Gitlab::View::Presenter::Simple
+    delegate :created_at, to: :subject
+
     def cards
       [
         Card.new(

app/views/admin/dev_ops_report/_report.html.haml

@@ -9,6 +9,8 @@
   = render 'no_data'
 - else
   .devops
+    .gl-my-3.gl-text-gray-400{ data: { testid: 'devops-score-note-text' } }
+      = s_('DevopsReport|DevOps score metrics are based on usage over the last 30 days. Last updated: %{timestamp}.').html_safe % { timestamp: @metric.created_at.strftime('%Y-%m-%d %H:%M') }
     .devops-header
       %h2.devops-header-title{ class: "devops-#{score_level(@metric.average_percentage_score)}-score" }
         = number_to_percentage(@metric.average_percentage_score, precision: 1)

changelogs/unreleased/296125-show-timeline-for-devops-score.yml

+---
+title: Add more explanation about the presented data and show the last updated time on the DevOps Score page
+merge_request: 55357
+author:
+type: added

ee/spec/views/admin/dev_ops_report/show.html.haml_spec.rb

@@ -27,6 +27,16 @@ RSpec.describe 'admin/dev_ops_report/show.html.haml' do
 
       expect(rendered).not_to have_selector('#devops-adoption')
     end
+
+    it 'shows the timestamp of the latest record' do
+      assign(:metric, create(:dev_ops_report_metric, created_at: Time.utc(2012, 5, 1, 14, 30)).present)
+
+      render
+
+      page = Capybara.string(rendered)
+      note_node = page.find("div[data-testid='devops-score-note-text']")
+      expect(note_node.text).to include('Last updated: 2012-05-01 14:30.')
+    end
   end
 
   context 'when show_adoption? returns true' do

locale/gitlab.pot

@@ -10535,6 +10535,9 @@ msgstr ""
 msgid "DevopsReport|DevOps Score"
 msgstr ""
 
+msgid "DevopsReport|DevOps score metrics are based on usage over the last 30 days. Last updated: %{timestamp}."
+msgstr ""
+
 msgid "DevopsReport|Score"
 msgstr ""