Update resource list

Author: Autogenerator Pipeline

generator/resources.json

@@ -876,6 +876,9 @@
   "Microsoft.CognitiveServices/accounts/privateEndpointConnections": [
     "2017-04-18"
   ],
+  "Microsoft.Communication/communicationServices": [
+    "2020-08-20-preview"
+  ],
   "Microsoft.Compute/availabilitySets": [
     "2015-05-01-preview",
     "2015-06-15",