Change label to be more consistent, not a series.

config/prometheus/additional_metrics.yml

@@ -155,7 +155,5 @@
     weight: 1
     queries:
     - query_range: 'sum(avg(rate(container_cpu_usage_seconds_total{container_name!="POD",environment="%{ci_environment_slug}"}[2m])) without (job)) * 100'
-      label: CPU
+      label: Average
       unit: "%"
\ No newline at end of file
-      series:
-        - label: cpu
\ No newline at end of file