Create a MetricTask that captures the MaxResidentSetSize from timeMethod. The task can be written by cargo-culting lsst.verify.tasks.TimingMetricTask. Add metrics for ApPipeTask and its direct subtasks to the default ap_verify config. Note that astropy supports data size units.
One outstanding question is how to define aggregation (which is still the responsibility of the MetricTask for now). For running time across multiple CCDs a sum is the natural choice; it's less natural for memory usage because the aggregated data IDs weren't necessarily run together.