bugfix: only cache successfult record #22019
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By default, yb will cache 60s (both good and bad record).
But DNS resolve use udp by default(boost:asio will using glibc getaddrinfo), sometimes the DNS rsp packet may lost, in this case yb will cache 'Host not found (authoritative)'.
For example, the DNS rsp packet is drop by network stack
Yb DNS resolve timeout, but will cache 60s error record(During this time period, the pod is ok). But yb will believe 'Host not found', which will cause the instance not available and some latency