Change ems refresh task complete messaging

taken from:
- ManageIQ#22465
- ManageIQ/manageiq-providers-autosde#228

Instead of displaying target information, this now displays a user friendly message in the ui

app/models/ems_refresh.rb

@@ -17,7 +17,7 @@ def self.debug_trace
   cache_with_timeout(:queue_timeout) { MiqEmsRefreshWorker.worker_settings[:queue_timeout] || 60.minutes }
 
   def self.queue_refresh_task(target, id = nil)
-    queue_refresh(target, id, :create_task => true)
+    queue_refresh(target, id, :create_task => true, :action => "EmsRefresh completed successfully")
   end
 
   def self.queue_refresh(target, id = nil, opts = {})