OperationailInsights: Cluster identity description change. (#12760)

* OperationalInsights: Changing property mutibality to default.

* Cluster identity description change.

Co-authored-by: Dudi Likvornik <dulikvor@microsoft.com>

Author: dulikvor

specification/operationalinsights/resource-manager/Microsoft.OperationalInsights/stable/2020-10-01/Clusters.json

@@ -542,7 +542,7 @@
         },
         "type": {
           "type": "string",
-          "description": "The type of identity used for the resource. The type 'SystemAssigned, UserAssigned' includes both an implicitly created identity and a set of user assigned identities.",
+          "description": "Type of managed service identity.",
           "enum": [
             "SystemAssigned",
             "UserAssigned",