Merge branch 'noteable-touch-return-object' into 'master'

Return the noteable in Note#touch_noteable

See merge request gitlab-org/gitlab-ce!15891

app/models/note.rb

@@ -401,6 +401,9 @@ class Note < ActiveRecord::Base
       end
 
     noteable_object&.touch
+
+    # We return the noteable object so we can re-use it in EE for ElasticSearch.
+    noteable_object
   end
 
   def banzai_render_context(field)