Add Container Registry on/off status to admin area

Display the on/off icon under the "Features" section of the admin area
for the Container Registry.

Closes !22805

CHANGELOG

@@ -43,6 +43,7 @@ v 8.13.0 (unreleased)
   - Fix broken repository 500 errors in project list
   - Close todos when accepting merge requests via the API !6486 (tonygambone)
   - Changed Slack service user referencing from full name to username (Sebastian Poxhofer) 
+  - Add Container Registry on/off status to Admin Area !6638 (the-undefined)
 
 v 8.12.4 (unreleased)
 

app/views/admin/dashboard/index.html.haml

@@ -63,6 +63,11 @@
           Reply by email
           %span.light.pull-right
             = boolean_to_icon Gitlab::IncomingEmail.enabled?
+        %p
+          Container Registry
+          %span.light.pull-right
+            = boolean_to_icon Gitlab.config.registry.enabled
+
       .col-md-4
         %h4
           Components