Add ability to email announcements to all users (#33928)

app/controllers/admin/announcements/previews_controller.rb

@@ -0,0 +1,16 @@
+# frozen_string_literal: true
+
+class Admin::Announcements::PreviewsController < Admin::BaseController
+  before_action :set_announcement
+
+  def show
+    authorize @announcement, :distribute?
+    @user_count = @announcement.scope_for_notification.count
+  end
+
+  private
+
+  def set_announcement
+    @announcement = Announcement.find(params[:announcement_id])
+  end
+end