add back scrape configs (#3433)

kubernetes/prometheus/extraScrapeConfigs.yaml

@@ -0,0 +1,12 @@
+extraScrapeConfigs: |
+  - job_name: opencost
+    honor_labels: true
+    scrape_interval: 1m
+    scrape_timeout: 10s
+    metrics_path: /metrics
+    scheme: http
+    dns_sd_configs:
+    - names:
+      - opencost.opencost
+      type: 'A'
+      port: 9003