@Override
    protected boolean isAllowed(ConfigValue configValue) {
        return false;
    }
Disallow any client configuration to be overridden via the connector configs by setting {@code connector.client.config.override.policy} to {@code None}.
This is the default behavior.
connect/runtime/src/main/java/org/apache/kafka/connect/connector/policy/NoneConnectorClientConfigOverridePolicy.java