ts: update the recording of changefeed child metrics#158889

craig[bot] merged 2 commits intocockroachdb:mastercockroachdb/cockroach:masterfrom

jasonlmfong:jf/ts-record-limited-set-child-metricsjasonlmfong/cockroach:jf/ts-record-limited-set-child-metricsCopy head branch name to clipboard