Fix tracking for shared billings partial

- Was using the wrong has format/keys for the tracking to pick it up
  consistently.
- refs:
  https://gitlab.com/gitlab-data/product-analytics/-/issues/158#note_835627466
  https://gitlab.com/gitlab-org/gitlab/-/issues/342853

ee/app/views/shared/billings/_billing_plans.html.haml

@@ -9,8 +9,7 @@
 
 - if show_plans?(namespace)
   - plans = billing_available_plans(plans_data, current_plan)
-
-  .billing-plans.gl-mt-7{ data: { track: { action: 'render', label: 'billing' } } }
+  .billing-plans.gl-mt-7{ data: { track_action: 'render', track_label: 'billing' } }
     - plans.each do |plan|
       - next if plan.hide_card
       - is_default_plan = current_plan.nil? && plan.default?