Squashed 'external/workload-automation/' changes from 4a9a2ad1..462a5b65

462a5b65 fw/output: add label property to Metric
7cd7b73f Fixed an error emptying the reading buffer of the poller

git-subtree-dir: external/workload-automation
git-subtree-split: 462a5b651a9360fcde34b26df51ded98699c1f38