in core/src/main/java/com/google/cloud/sql/core/DefaultConnectionInfoRepository.java [377:383]
private static boolean isCasManagedCertificate(String serverCaMode) {
boolean useLegacyValidation =
serverCaMode == null
|| serverCaMode.isEmpty()
|| "GOOGLE_MANAGED_INTERNAL_CA".equals(serverCaMode);
return !useLegacyValidation;
}