Extract hook methods from group policies with EE-specific implementation

app/policies/group_member_policy.rb

@@ -16,8 +16,11 @@ class GroupMemberPolicy < BasePolicy
       can! :destroy_group_member
     end
 
-    # EE-only
-    can_override = Ability.allowed?(@user, :override_group_member, group)
+    additional_rules!
+  end
+
+  def additional_rules!
+    can_override = Ability.allowed?(@user, :override_group_member, @subject.group)
 
     if can_override
       can! :override_group_member if @subject.ldap?

app/policies/group_policy.rb

@@ -34,11 +34,7 @@ class GroupPolicy < BasePolicy
       can! :request_access
     end
 
-    # EE-only
-    if @subject.ldap_synced?
-      cannot! :admin_group_member
-      can! :override_group_member if owner
-    end
+    additional_rules!(master)
   end
 
   def can_read_group?
@@ -49,4 +45,11 @@ class GroupPolicy < BasePolicy
 
     GroupProjectsFinder.new(@subject).execute(@user).any?
   end
+
+  def additional_rules!(master)
+    if @subject.ldap_synced?
+      cannot! :admin_group_member
+      can! :override_group_member if master
+    end
+  end
 end