Fix feature flag check for productivity analytics

In !18754 (merged) we have enabled the PA feature flag by default, however we missed setting the default_enabled flag for the routes. This results in 404 error, when opening the analytics workspace.

Steps to reproduce:

1. Make sure all analytics features are disabled and deleted. Feature::FlipperFeature.all.select { |a| a.key.include?("analytics") }.map(&:destroy)
2. Restart the server (FFs are cached)
3. Go to /analytics
4. You should see 404 error