Replace deprecated script with gradlew #697

Job	Run time
build (cfi-tests, 8)	8m 16s
build (cfi-tests, 11)	9m 19s
build (cfi-tests, 17)	9m 1s
build (downstream-ontology, 8)	7m 47s
build (downstream-ontology, 11)	9m 23s
build (downstream-ontology, 17)	8m 56s
build (downstream-security-demo, 8)	7m 51s
build (downstream-security-demo, 11)	9m 0s
build (downstream-security-demo, 17)	8m 58s
build (downstream-universe, 8)	5m 18s
build (downstream-universe, 11)	6m 21s
build (downstream-universe, 17)	6m 5s
	1h 36m 15s

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