address metrics-related error and remove high cardinality labels

I'm still not sure why this error message, "Call tuples failed in returnOnFirstError. Error: Error: Added label "message" is not included in initial labelset: [ 'error', 'reqId' ]." comes through, I don't see where we might be knowingly feeding function sendImplementationErrorMetrics an object with that specific label. Perhaps there is some labeling occurring someplace? I'm curious what might change if we add the "message" label to this Metric.

Bug: T380649

Bug: T381317