Revert "clean up lazy loading of serialization support for

ActiveRecord::Base and ActionController::Base"

The whole idea of having a lazy hook is that it can be executed
in the context of different targets. The moment you hardcode the class,
the hooks can no longer run in the proper context.

This reverts commit 506e2ac9ad.

lib/active_model_serializers.rb

@@ -57,7 +57,7 @@ module ActiveModel::SerializerSupport
 end
 
 ActiveSupport.on_load(:active_record) do
-  ActiveRecord::Base.send(:include, ActiveModel::SerializerSupport)
+  include ActiveModel::SerializerSupport
 end
 
 module ActiveModel::ArraySerializerSupport
@@ -78,7 +78,7 @@ begin
   require 'action_controller/serialization'
 
   ActiveSupport.on_load(:action_controller) do
-    ActionController::Base.send(:include, ActionController::Serialization)
+    include ::ActionController::Serialization
   end
 rescue LoadError => ex
   # rails on installed, continuing