Control alert management feature flag per project

Enable/disable feature flag `alert_management_create_alert_issue`
per project rather than globally.

app/controllers/projects/alert_management_controller.rb

@@ -3,7 +3,7 @@
 class Projects::AlertManagementController < Projects::ApplicationController
   before_action :authorize_read_alert_management_alert!
   before_action do
-    push_frontend_feature_flag(:alert_management_create_alert_issue)
+    push_frontend_feature_flag(:alert_management_create_alert_issue, project)
     push_frontend_feature_flag(:alert_assignee, project)
   end