paas-s3-broker: bump to ..., provide with common user policy, expand custom-broker-acceptance-tests #2555

Job	Run time
tests (lint)	2m 36s
tests (config_spec)	1m 12s
tests (tools_spec)	2m 8s
tests (concourse_spec)	1m 41s
tests (manifests_spec)	4m 13s
tests (terraform_spec)	1m 27s
tests (platform_tests_spec)	1m 29s
tests (compile_platform_tests)	1m 34s
	16m 20s

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