Change the unit primitive for troubleshoot job

What does this MR do and why?

This adds the unit primitive for the /troubleshoot_job slash command tool.

Similar too: !157606 (merged)

Part of making this available to Enterprise Duo customers only. Issue: #457573 (closed)

ee/app/controllers/ee/projects/jobs_controller.rb

@@ -7,6 +7,7 @@ module JobsController
 
       prepended do
         before_action only: [:show] do
+          push_frontend_ability(ability: :troubleshoot_job_with_ai, resource: @build, user: @current_user)
           push_frontend_feature_flag(:root_cause_analysis_duo, @current_user)
         end
       end