Unlike test components, benchmarks are deployed to specific machines, eg
"bsw-01" instead of "bsw".

This typo was copied to several builds.

Data shows benchmark variance to vary widely by benchmark and hardware.
PerfBuilder now supports a custom_iterations_fn parameter, which inverts
control over iterations.

Performance components can define their own function to customize
iterations, and pass it to the builder.

Reboot if gpu hang occurs during benchmark. However, Don't identify
gpu_hanging test for perf builds.  There are no tests to iterate in this
case.