chore(googleworkspace): name the Policy API reducer the precedence rule implements (#13125)

prowler/providers/googleworkspace/lib/service/service.py

@@ -146,10 +146,17 @@ class GoogleWorkspaceService:
 
         The API returns every policy that exists for a setting: Google's
         SYSTEM defaults next to the ADMIN policy saved in the Admin console.
-        The value in force is the one with the greatest policyQuery.sortOrder
-        (Policy API concepts, Max and Merge reducers), not the last one
-        listed. Policies without a sort order keep the API order, so the last
-        one wins. Rules are not reduced: each policy is a distinct rule.
+        The value in force is the one with the greatest policyQuery.sortOrder,
+        which is the Policy API's Max reducer, not the last one listed. Rule
+        settings use the List reducer and are not reduced here: each policy is
+        a distinct rule. Settings resolved with the Merge, MaxMap or MergeMap
+        reducers combine several policies; this method keeps the greatest one
+        for them too, which is exact only when that policy supplies the whole
+        reduced value: every field, plus the array values Merge concatenates
+        and the keyed entries MaxMap and MergeMap keep from policies with a
+        lower sortOrder. Policies saved from the Admin console carry every
+        field of the setting. Policies without a sort order keep the API order,
+        so the last one wins.
         """
         kept: list[dict] = []
         position: dict[str, int] = {}