chore: use require-hashes option for owlbot docker image (#1592) (#1264)
chore: use require-hashes option for owlbot docker image (#1592) (#1264)

* chore: use require-hashes option for owlbot docker image

Co-authored-by: Mike Eltsufin <6be2e68057643604526e642c9a0796521316242c@google.com>
Source-Link: https://github.com/googleapis/synthtool/commit/d7d1a87a7f0df9dd494617283ec0fab4b094687d
Post-Processor: 48d5800083e04fbe06b7d85b0e411aebd73b5710@sha256:faab4ce05feb201db2dbbec4eff44b1f132d5e0316f7ba1c25e538516973fae3

Co-authored-by: Owl Bot <7f39581e9a7ddb69f3fa3e6fc69a582ea2916fc9@users.noreply.github.com>
Co-authored-by: Mike Eltsufin <6be2e68057643604526e642c9a0796521316242c@google.com>
Co-authored-by: Diego Alonso Marquez Palacios <10508b2cf21784d8ad6cf3c79d3cfbef487023ad@google.com>
googleapis/java-automl,googleapis/java-automl,googleapis/java-automl