v2: Make it easy to set static labels

[petewall]

I'd love to be able to do this:

podLogs:
  staticLabels:
    region: central

without needing to do this:

podLogs:
  extraLogProcessingStages: |
    stage.static_labels {
      values = {
        region = "central",
      }
    }

[ceastman-r7]

@petewall In addition to the podLogs feature, can you do this for metrics, traces and profiles? I am looking to add some labels onto these as well that will help with setting up lbac (In the future when its available for these other observability pillars).