* Add OomKilled field to executor proto format
* Teach linux executor to detect and report OOMs
* Teach exec driver to propagate OOMKill information
* Fix data race
* use tail /dev/zero to create oom condition
* use new test framework
* minor tweaks to executor test
* add cl entry
* remove type conversion
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Co-authored-by: Marvin Chin <marvinchin@users.noreply.github.com>
Co-authored-by: Seth Hoenig <shoenig@duck.com>
