[apache#5336]feat(auth-ranger): Remove MANAGED_BY_GRAVITINO limit and…

… compatible for existing ranger policy

authorizations/authorization-ranger/src/main/java/org/apache/gravitino/authorization/ranger/RangerHelper.java

@@ -79,7 +79,9 @@ public RangerHelper(
   }
 
   /**
-   * For easy management, each privilege will create one RangerPolicyItemAccess in the policy.
+   * There are two types of policy items:
+   * Gravitino managed policy items: They contain one privilege each.
+   * User-defined policy items: They could contain multiple privileges and not be managed and checked by Gravitino.
    *
    * @param policyItem The policy item to check
    * @throws AuthorizationPluginException If the policy item contains more than one access type