Switch to n1-highcpu-32 for gcb, fixes arrow benchmark hang. (#955)
Switch to n1-highcpu-32 for gcb, fixes arrow benchmark hang. (#955)

* Switch to n1-highcpu-32 for gcb, fixes arrow benchmark hang.

This also matches OSS-Fuzz configuration.
See
https://console.cloud.google.com/cloud-build/builds/d0876d12-65f6-4cc2-bc6c-7a8a04cbf680?authuser=0&project=fuzzbench
(failure)
vs
https://console.cloud.google.com/cloud-build/builds/30a99746-4a1a-4421-8d93-428fa51957f3?authuser=0&project=fuzzbench
(success)

* Format.
google/fuzzbench,google/fuzzbench,google/fuzzbench,google/fuzzbench,google/fuzzbench