Draft: Adds Grafana Time Series plugin support

As part of gitlab-com/gl-infra/observability/team#2573.

libsonnet/gitlab-dashboards/key_metrics.libsonnet

@@ -2,7 +2,7 @@ local aggregationSets = (import '../../metrics-catalog/gitlab-metrics-config.lib
 local grafana = import 'github.com/grafana/grafonnet-lib/grafonnet/grafana.libsonnet';
 local layout = import 'grafana/layout.libsonnet';
 local singleMetricRow = import '../key-metric-panels/single-metric-row.libsonnet';
-local utilizationRatesPanel = import 'key-metric-panels/utilization-rates-panel.libsonnet';
+local utilizationRatesPanel = import '../key-metric-panels/utilization-rates-panel.libsonnet';
 local metricsCatalog = import 'servicemetrics/metrics-catalog.libsonnet';
 local row = grafana.row;
 
@@ -110,7 +110,7 @@ local getColumnWidths(
       (
         if showSaturationCell then
           [[
-            utilizationRatesPanel.panel(
+            utilizationRatesPanel.timeSeriesPanel(
               serviceType,
               selectorHash=selectorHashWithShard,
               compact=compact,