chore(main): release 1.20.0

[release-please]

🤖 I have created a release beep boop

1.20.0

1.20.0 (2023-09-28)

Features

• [alloydb] Add support to generate client certificate and get connection info for auth proxy in AlloyDB v1 (#9903) (16f1b33)
• [dialogflow-cx] add support for AdvancedSettings (#9905) (f39cd4c)
• [dialogflow] Add the enable_partial_automated_agent_reply flag (#9906) (e88fe30)

Bug Fixes

• [run] Removes accidentally exposed field service.traffic_tags_cleanup_threshold in Cloud Run Service (#9908) (ad81708)
• deps: update dependency com.google.apis:google-api-services-storage to v1-rev20230926-2.0.0 (#9911) (d7f5cc9)
• deps: update dependency com.google.cloud:google-cloud-pubsub-bom to v1.125.3 (#9910) (52dc784)
• deps: update dependency com.google.cloud:google-cloud-pubsub-bom to v1.125.3 (#9912) (f49e2d9)

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[release-please]

🤖 Release is at https://github.com/googleapis/google-cloud-java/releases/tag/v1.20.0 🌻

[release-trigger]

Triggered job: cloud-devrel/client-libraries/java/google-cloud-java/release/stage (2023-09-28T17:28:25.676Z)

To trigger again, remove the autorelease: triggered label (in a few minutes).

[release-tool-publish-reporter]

The release build has started, the log can be viewed here. 🌻