Geo: Add settings page empty state

ee/app/views/admin/application_settings/_geo.html.haml

-- return unless Gitlab::Geo.license_allows?
-
-%section.settings.as-geo.no-animate#js-geo-settings{ class: ('expanded' if expanded) }
+- if Gitlab::Geo.license_allows?
+  %section.settings.as-geo.no-animate#js-geo-settings{ class: ('expanded' if expanded) }
     .settings-header
       %h4
         = _('GitLab Geo')
@@ -24,3 +23,5 @@
               status will time out.
 
         = f.submit 'Save changes', class: "btn btn-success"
+- else
+  = render 'shared/empty_states/geo'

ee/changelogs/unreleased/8380-geo-settings-empty-state.yml

+---
+title: "Geo: Add settings page empty state"
+merge_request: 9415
+author:
+type: changed

ee/spec/features/admin/admin_settings_spec.rb

@@ -9,7 +9,9 @@ describe 'Admin updates EE-only settings' do
     allow(License).to receive(:feature_available?).and_return(true)
   end
 
-  it 'Modify GitLab Geo settings' do
+  context 'Geo settings' do
+    context 'when the license has Geo feature' do
+      it 'allows users to change Geo settings' do
         visit geo_admin_application_settings_path
         page.within('.as-geo') do
           fill_in 'Connection timeout', with: 15
@@ -19,6 +21,18 @@ describe 'Admin updates EE-only settings' do
         expect(Gitlab::CurrentSettings.geo_status_timeout).to eq(15)
         expect(page).to have_content "Application settings saved successfully"
       end
+    end
+
+    context 'when the license does not have Geo feature' do
+      it 'shows empty page' do
+        allow(License).to receive(:feature_available?).and_return(false)
+
+        visit geo_admin_application_settings_path
+
+        expect(page).to have_content "Discover GitLab Geo"
+      end
+    end
+  end
 
   it 'Enable external authentication' do
     visit admin_application_settings_path