add `dev_random example`, remove `device` field #258

Job	Run time
Run check udeps	2m 23s
Run check udeps	2m 23s
Run check treefmt --fail-on-change	46s
Run check treefmt --fail-on-change	46s
Run check audit --deny warnings	1m 22s
Run check audit --deny warnings	1m 22s
Run hypervisor with example hello_part	3m 0s
Run hypervisor with example hello_part	3m 0s
Run hypervisor with example fuel_tank	2m 50s
Run hypervisor with example fuel_tank	2m 50s
Run hypervisor with example ping	3m 32s
Run hypervisor with example ping	3m 32s
Run hypervisor with example dev_random	3m 55s
Run hypervisor with example dev_random	3m 38s
	35m 19s

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