[tests] enable `OT_PLATFORM_LOG_CRASH_DUMP` #1450

Job	Run time
Examples	2m 48s
Stress network-forming	23m 5s
Unittests	3m 0s
Stress commissioning	16m 51s
Stress connectivity	15m 52s
Stress network-latency	2m 35s
Stress multicast-performance	2m 29s
Stress otns-performance	2m 36s
upload-coverage	18s
	1h 9m 34s

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