feat(cloudrun): allow adding new readiness probe to cloud run

[mysterytony]

Description

cloudrunci updates to support readiness probe additions in #5368

Note: Before submitting a pull request, please open an issue for discussion if you are not associated with Google.

Checklist

• I have followed Contributing Guidelines from CONTRIBUTING.MD
• Tests pass: go test -v ./.. (see Testing)
• Code formatted: gofmt (see Formatting)
• Vetting pass: go vet (see Formatting)
• These samples need a new API enabled in testing projects to pass (let us know which ones)
• These samples need a new/updated env vars in testing projects set to pass (let us know which ones)
• This sample adds a new sample directory, and I updated the CODEOWNERS file with the codeowners for this sample
• This sample adds a new Product API, and I updated the Blunderbuss issue/PR auto-assigner with the codeowners for this sample
• Please merge this PR for me once it is approved

[iennae]

/gemini review

[gemini-code-assist]

Code Review

This pull request adds support for readiness probes to Cloud Run services. The implementation is mostly correct, but there are a few areas for improvement. I've identified an issue with how the readiness probe arguments are constructed, which could lead to invalid commands being generated. I've also suggested a refactoring to use named structs for the probe configuration to improve code clarity and maintainability, which would also simplify the new tests.

[mysterytony]

Hi! Thanks for the review, I've addressed the comments, please take another look.

[briandorsey]

Thanks for breaking out these CI support changes into a separate PR! Look good overall. I added one comment. Tested manually and tests pass.

Started an integration test run as well. Will merge after that assuming no Cloud Run related failures.