add updated at to project package show api

app/api/mobile/entities/project_package.rb

@@ -20,6 +20,9 @@ module Mobile
       expose :contact_name, if: ->(package, opts){ opts[:user].id == package.creator_id || opts[:user].admin? || opts[:user].business?  }
       expose :contact_phone, if: ->(package, opts){ opts[:user].id == package.creator_id || opts[:user].admin? || opts[:user].business?  }
 
+      expose :updated_at do |package, _|
+        package.updated_at.try(:utc).try(:iso8601)
+      end
       expose :deadline_at do |package, _|
         package.deadline_at.try(:utc).try(:iso8601)
       end