searchable: refactor searchable_includes.

Pass searchable associations directly to search_attributes instead of
defining them separately in searchable_includes.

app/models/user_feedback.rb

@@ -30,7 +30,7 @@ class UserFeedback < ApplicationRecord
     end
 
     def search(params)
-      q = search_attributes(params, :id, :created_at, :updated_at, :category, :body, :is_deleted)
+      q = search_attributes(params, :id, :created_at, :updated_at, :category, :body, :is_deleted, :creator, :user)
       q = q.text_attribute_matches(:body, params[:body_matches])
 
       q.apply_default_order(params)
@@ -56,10 +56,6 @@ class UserFeedback < ApplicationRecord
     Dmail.create_automated(:to_id => user_id, :title => "Your user record has been updated", :body => body)
   end
 
-  def self.searchable_includes
-    [:creator, :user]
-  end
-
   def self.available_includes
     [:creator, :user]
   end