Change default --ssh_control_path from %C to %h (remote hostname) to shorten it,
Change default --ssh_control_path from %C to %h (remote hostname) to shorten it,

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Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=275932567

GoogleCloudPlatform/PerfKitBenchmarker,GoogleCloudPlatform/PerfKitBenchmarker,GoogleCloudPlatform/PerfKitBenchmarker,GoogleCloudPlatform/PerfKitBenchmarker