This change updates the fluentd chart to use the native
fluent-plugin-prometheus for metric production. This plugin
provides more detailed metrics about fluentd's operations,
specifically regarding input and output statistics.
https://github.com/fluent/fluent-plugin-prometheus
Using the plugin, each fluentd pod produces metrics, so
scape annotations have been added to the pod spec. The
zuul check on metric producers has been updated to account
for this.
Depends-On: https://review.opendev.org/714167
Change-Id: I809356d92b0cff1e31cb2062102bbedefd4843fd
9d2e08f1a4