Pointing to fluentbit version 0.15.8-bb.1

Summary

0.15.8-bb.1 fixes issue where upstream update to chart removed namespace definition from the grafana dashboard configmap resource within the fluentbit chart.

chart/values.yaml

@@ -256,7 +256,7 @@ fluentbit:
   git:
     repo: https://repo1.dso.mil/platform-one/big-bang/apps/core/fluentbit.git
     path: "./chart"
-    tag: "0.15.8-bb.0"
+    tag: "0.15.8-bb.1"
   values: {}
 
   # -- Post Renderers.  See docs/postrenders.md