Replace deprecated script with gradlew #689

Job	Run time
build (cfi-tests, 8)	8m 12s
build (cfi-tests, 11)	9m 2s
build (cfi-tests, 17)	8m 27s
build (downstream-ontology, 8)	8m 38s
build (downstream-ontology, 11)	9m 4s
build (downstream-ontology, 17)	9m 4s
build (downstream-security-demo, 8)	7m 45s
build (downstream-security-demo, 11)	8m 57s
build (downstream-security-demo, 17)	9m 48s
build (downstream-universe, 8)	5m 15s
build (downstream-universe, 11)	6m 10s
build (downstream-universe, 17)	6m 5s
	1h 36m 27s

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