ecs: fix ec course support position

app/services/ecs/save_graduation_course_supports_service.rb

@@ -9,6 +9,8 @@ class Ecs::SaveGraduationCourseSupportsService < ApplicationService
   end
 
   def call
+    set_course_supports_position!
+
     Ecs::SaveGraduationCourseSupportForm.new(params).validate!
 
     accepts_attributes = build_accepts_nested_attributes(
@@ -20,4 +22,10 @@ class Ecs::SaveGraduationCourseSupportsService < ApplicationService
     graduation_subitem.save!
     graduation_subitem
   end
+
+  def set_course_supports_position!
+    params[:course_supports].each_with_index do |item, index|
+      item[:position] = index + 1
+    end
+  end
 end