FLINK-4402 fixed the following metrics names:
metrics.scope.tm.task → metrics.scope.task
metrics.scope.tm.operator → metrics.scope.operator
However, the 1.2.0 documentation lists the incorrect metric names again.
As a side note, it would be convenient to have all of the configuration options documented in a machine readable format. To build docker images I process the config file with sed to extract the options and turn them into env vars, which is how I noticed this issue.