Remove default from unixPermissions (#14712)

Co-authored-by: Audunn Baldvinsson <[email protected]>

Author: audunn

specification/netapp/resource-manager/Microsoft.NetApp/stable/2021-04-01/netapp.json

@@ -3833,8 +3833,7 @@
           "minLength": 4,
           "maxLength": 4,
           "x-nullable": true,
-          "example": "0770",
-          "default": "0770"
+          "example": "0770"
         }
       }
     },