Move Order callback entirely into service

app/models/spree/order.rb

@@ -104,7 +104,7 @@ module Spree
     before_save :update_shipping_fees!, if: :complete?
     before_save :update_payment_fees!, if: :complete?
 
-    after_save_commit :save_default_addresses
+    after_save_commit DefaultAddressUpdater
 
     # -- Scopes
     scope :not_empty, -> {
@@ -745,11 +745,5 @@ module Spree
 
       pending_payments.first.update_attribute :amount, total
     end
-
-    def save_default_addresses
-      return unless save_bill_address || save_ship_address
-
-      DefaultAddressUpdater.new(self).call
-    end
   end
 end

app/services/default_address_updater.rb

@@ -1,6 +1,12 @@
 # frozen_string_literal: true
 
 class DefaultAddressUpdater
+  def self.after_commit(order)
+    return unless order.save_bill_address || order.save_ship_address
+
+    new(order).call
+  end
+
   def initialize(order)
     @order = order
   end