Rename platform_load Stackdriver metric (#816)
Rename platform_load Stackdriver metric (#816)

The aggregate metric "unfinished_jobs" is now called "required_workers" to reflect the reality of the metric: A job that is blocked by another one is technically unfinished, but doesn't require a worker (yet).
bazelbuild/continuous-integration,bazelbuild/continuous-integration,bazelbuild/continuous-integration,bazelbuild/continuous-integration,bazelbuild/continuous-integration,bazelbuild/continuous-integration,bazelbuild/continuous-integration,bazelbuild/continuous-integration