update gapic-generator hash (#651)
update gapic-generator hash (#651)

Changes included are fixes:

- samplegen: add sample_config.proto to the config_java_proto BUILD target https://github.com/googleapis/gapic-generator/pull/2852
- go: URL encode x-goog-request-params https://github.com/googleapis/gapic-generator/pull/2851
- ruby: ake it possible to pass metadata to the operations client https://github.com/googleapis/gapic-generator/pull/2856
googleapis/artman,googleapis/artman,googleapis/artman