Reuse `Gitlab::Allowable` mixin in base service

app/services/base_service.rb

 class BaseService
+  include Gitlab::Allowable
   include Gitlab::CurrentSettings
 
   attr_accessor :project, :current_user, :params
@@ -7,10 +8,6 @@ class BaseService
     @project, @current_user, @params = project, user, params.dup
   end
 
-  def can?(object, action, subject)
-    Ability.allowed?(object, action, subject)
-  end
-
   def notification_service
     NotificationService.new
   end