[
  {
    "method": "CreateExternalAccountKey",
    "client": "PublicCertificateAuthorityServiceClient",
    "arguments": {
      "parent": "projects/${PROJECT_ID}/locations/global",
      "externalAccountKey": {}
    }
  }
]
Add smoke test for Google.Cloud.Security.PublicCA.V1Beta1
tests: Add smoke test for Google.Cloud.Security.PublicCA.V1Beta1
