paas-s3-broker: bump to ..., provide with common user policy, expand custom-broker-acceptance-tests #2559

Job	Run time
tests (lint)	3m 15s
tests (config_spec)	1m 5s
tests (tools_spec)	2m 22s
tests (concourse_spec)	2m 0s
tests (manifests_spec)	3m 36s
tests (terraform_spec)	1m 38s
tests (platform_tests_spec)	1m 45s
tests (compile_platform_tests)	1m 25s
	17m 6s

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