Move after_action to the concern

This fixes failing specs on production in which `after_action` callback seems to be executed after tables are truncated.

app/controllers/admin/press_summaries_controller.rb

@@ -1,4 +1,3 @@
 class Admin::PressSummariesController < Admin::BaseController
-  after_action :log_event, only: [:create, :update, :submit, :signoff]
   include PressSummaryMixin
 end

app/controllers/assessor/press_summaries_controller.rb

@@ -1,4 +1,3 @@
 class Assessor::PressSummariesController < Assessor::BaseController
-  after_action :log_event, only: [:create, :update, :submit, :signoff]
   include PressSummaryMixin
 end

app/controllers/concerns/press_summary_mixin.rb

@@ -4,6 +4,7 @@ module PressSummaryMixin
   def self.included(base)
     base.before_action :load_form_answer
     base.before_action :load_press_summary, except: :create
+    base.after_action :log_event, only: [:create, :update, :submit, :signoff]
   end
 
   def create