fix(kms): certificate chain type to array of strings

[modular-magician]

The response type for KeyOperationAttestation CertificateChains is an array of strings. This is also what documentation says. https://cloud.google.com/kms/docs/reference/rest/v1/KeyOperationAttestation#certificatechains

However the provider spec for that property lists them as strings, so terraform will panic whenever a key version is created with HSM that uses these certificates as the types are mismatched. This PR fixes this so the type is an array of strings, as well as adding an AccTest for HSM key version

Fixes hashicorp/terraform-provider-google#13924

Release Note Template for Downstream PRs (will be copied)

kms: fixed issue where `google_kms_crypto_key_version.attestation.cert_chains` properties were incorrectly set to type string

Derived from GoogleCloudPlatform/magic-modules#9582