feat: migrate google-devtools-containeranalysis to librarian

[suztomo]

Migrate google-devtools-containeranalysis to Librarian.

This migration has been configured to maintain 100% backward compatibility with the current main branch:

• Grafeas v1beta1 Client Preserved: The GrafeasV1Beta1Client remains generated and exported in the v1beta1 package.
• Grafeas v1 Path Helpers Preserved: The path helper methods (notePath, occurrencePath etc.) on ContainerAnalysisClient (v1) are preserved by including Grafeas v1 protos in the generation pool.
• No new exports: The GrafeasClient (v1) remains excluded and is NOT exported at the top level (matching the current state on main).

This ensures there are no customer-facing breaking changes introduced by the migration to Librarian.

Special Configurations in librarian.yaml

To maintain this compatibility, the following non-standard configurations were added to librarian.yaml:

1. Multiple API Versions: Both google/devtools/containeranalysis/v1 and google/devtools/containeranalysis/v1beta1 are configured for generation.
2. Additional Protos:
   • grafeas/v1/grafeas.proto is added to v1 to generate path helpers on ContainerAnalysisClient.
   • google/devtools/containeranalysis/v1beta1/grafeas/grafeas.proto is added to v1beta1 to generate GrafeasV1Beta1Client.
3. Preserved Dependency: @google-cloud/grafeas is listed in nodejs.dependencies to preserve the existing dependency. This is required because ContainerAnalysisClient (v1) has a custom hand-written method getGrafeasClient() that returns an instance of GrafeasClient from that package.

Note on Grafeas v1 Cleanup (Workaround)

To preserve the path helpers on ContainerAnalysisClient (v1), we included grafeas/v1/grafeas.proto in the generation. This automatically generates the GrafeasClient (v1), its samples, and exports it.

Because we discard GrafeasClient (v1) (as configured in librarian.js:L107-111 to avoid duplicating @google-cloud/grafeas), we must perform post-processing cleanup in librarian.js (deleting the client files, removing exports from index files, deleting generated samples, and cleaning up system-test fixture samples).

This post-processing complexity is a workaround and has been filed as an issue to be addressed in the future: googleapis/librarian#6390.

[gemini-code-assist]

Code Review

This pull request removes Grafeas-related APIs, protos, generated samples, tests, and path templates from the @google-cloud/containeranalysis package, leaving only the core container analysis service. It also updates configuration files, such as adding timeouts to IAM policy methods and updating repository metadata. The review feedback highlights that manual edits to generated client configuration files, specifically the removal of codeowner_team and requires_billing fields in .repo-metadata.json, are not allowed and should instead be updated upstream in the generator.