Set @body_classes to admin layout (#9081)

app/controllers/settings/sessions_controller.rb

@@ -2,6 +2,7 @@
 
 class Settings::SessionsController < ApplicationController
   before_action :set_session, only: :destroy
+  before_action :set_body_classes
 
   def destroy
     @session.destroy!
@@ -14,4 +15,8 @@ class Settings::SessionsController < ApplicationController
   def set_session
     @session = current_user.session_activations.find(params[:id])
   end
+
+  def set_body_classes
+    @body_classes = 'admin'
+  end
 end