callout when ci variables are protected by default

app/views/ci/variables/_index.html.haml

 - save_endpoint = local_assigns.fetch(:save_endpoint, nil)
+- if ci_variable_protected_by_default?
+  %p.settings-message.text-center
+    - link_start = '<a href="%{url}">'.html_safe % { url: help_page_path('ci/variables/README', anchor: 'protected-variables') }
+    = s_('Environment variables are configured by your administrator to be %{link_start}protected%{link_end} by default').html_safe % { link_start: link_start, link_end: '</a>'.html_safe }
+
 .row
   .col-lg-12.js-ci-variable-list-section{ data: { save_endpoint: save_endpoint } }
     .hide.alert.alert-danger.js-ci-variable-error-box

locale/gitlab.pot

@@ -2675,6 +2675,9 @@ msgstr ""
 msgid "Environment variables are applied to environments via the runner. They can be protected by only exposing them to protected branches or tags. You can use environment variables for passwords, secret keys, or whatever you want."
 msgstr ""
+msgid "Environment variables are configured by your administrator to be %{link_start}protected%{link_end} by default"
+msgstr ""
+
 msgid "Environments"
 msgstr ""

spec/support/features/variable_list_shared_examples.rb

@@ -67,11 +67,11 @@ shared_examples 'variable list' do
     context 'application setting is true' do
       before do
         stub_application_setting(protected_ci_variables: true)
-      end
-      it 'defaults to protected' do
         visit page_path
+      end
+      it 'defaults to protected' do
         page.within('.js-ci-variable-list-section .js-row:last-child') do
           find('.js-ci-variable-input-key').set('key')
         end
@@ -80,16 +80,20 @@ shared_examples 'variable list' do
         expect(values).to eq %w(false true true)
       end
+
+      it 'shows a message regarding the changed default' do
+        expect(page).to have_content 'Environment variables are configured by your administrator to be protected by default'
+      end
     end
     context 'application setting is false' do
       before do
         stub_application_setting(protected_ci_variables: false)
-      end
-      it 'defaults to unprotected' do
         visit page_path
+      end
+      it 'defaults to unprotected' do
         page.within('.js-ci-variable-list-section .js-row:last-child') do
           find('.js-ci-variable-input-key').set('key')
         end
@@ -98,6 +102,10 @@ shared_examples 'variable list' do
         expect(values).to eq %w(false false false)
       end
+
+      it 'does not show a message regarding the default' do
+        expect(page).not_to have_content 'Environment variables are configured by your administrator to be protected by default'
+      end
     end
   end