Generated OpenAPI files wrongly encode enums

[bripkens]

The repo supports the creation of OpenAPI files via make gen-openapi. Unfortunately, the generated files wrongly encode enums (as strings vs. numbers):

Examples

    "v1SeverityNumber": {
      "type": "string",
      "enum": [
        "SEVERITY_NUMBER_UNSPECIFIED",
        "SEVERITY_NUMBER_TRACE",
        "SEVERITY_NUMBER_TRACE2",
        "SEVERITY_NUMBER_TRACE3",
        "SEVERITY_NUMBER_TRACE4",
        "SEVERITY_NUMBER_DEBUG",
        "SEVERITY_NUMBER_DEBUG2",
        "SEVERITY_NUMBER_DEBUG3",
        "SEVERITY_NUMBER_DEBUG4",
        "SEVERITY_NUMBER_INFO",
        "SEVERITY_NUMBER_INFO2",
        "SEVERITY_NUMBER_INFO3",
        "SEVERITY_NUMBER_INFO4",
        "SEVERITY_NUMBER_WARN",
        "SEVERITY_NUMBER_WARN2",
        "SEVERITY_NUMBER_WARN3",
        "SEVERITY_NUMBER_WARN4",
        "SEVERITY_NUMBER_ERROR",
        "SEVERITY_NUMBER_ERROR2",
        "SEVERITY_NUMBER_ERROR3",
        "SEVERITY_NUMBER_ERROR4",
        "SEVERITY_NUMBER_FATAL",
        "SEVERITY_NUMBER_FATAL2",
        "SEVERITY_NUMBER_FATAL3",
        "SEVERITY_NUMBER_FATAL4"
      ],
      "default": "SEVERITY_NUMBER_UNSPECIFIED",
      "description": "Possible values for LogRecord.SeverityNumber.\n\n - SEVERITY_NUMBER_UNSPECIFIED: UNSPECIFIED is the default SeverityNumber, it MUST NOT be used."
    }