Carry over missing Acr properties from previous version (#14490)

Author: naveedaz

specification/web/resource-manager/Microsoft.Web/stable/2021-01-01/CommonDefinitions.json

@@ -2462,6 +2462,14 @@
           "description": "<code>true</code> if HTTP logging is enabled; otherwise, <code>false</code>.",
           "type": "boolean"
         },
+        "acrUseManagedIdentityCreds": {
+          "description": "Flag to use Managed Identity Creds for ACR pull",
+          "type": "boolean"
+        },
+        "acrUserManagedIdentityID": {
+          "description": "If using user managed identity, the user managed identity ClientId",
+          "type": "string"
+        },
         "logsDirectorySizeLimit": {
           "format": "int32",
           "description": "HTTP logs directory size limit.",