Refactor `AbstractSimpleTransportTestCase` and `MockTransportService` to not use `Version.transportVersion` 
x-pack/plugin/security/src/test/java/org/elasticsearch/xpack/security/transport/netty4/SimpleSecurityNetty4ServerTransportTests.java
"server_node_id",
                    new TransportAddress(serverAddress),
                    attributes,
                    DiscoveryNodeRole.roles(),
                    Version.CURRENT
                );
                ConnectTransportException connectException = expectThrows(
                    ConnectTransportException.class,
                    () -> connectToNode(serviceC, node, TestProfiles.LIGHT_PROFILE)
                );
                assertThat(connectException.getMessage(), containsString("invalid DiscoveryNode server_name [invalid_hostname]"));
            }
        }
    }
    public void testSecurityClientAuthenticationConfigs() throws Exception {
        Path testnodeCert = getDataPath("/org/elasticsearch/xpack/security/transport/ssl/certs/simple/testnode.crt");
        Path testnodeKey = getDataPath("/org/elasticsearch/xpack/security/transport/ssl/certs/simple/testnode.pem");
        Transport.Connection connection1 = serviceA.getConnection(serviceB.getLocalNode());
        SSLEngine sslEngine = getSSLEngine(connection1);
        assertThat(sslEngine, notNullValue());
        
        assertThat(sslEngine.getNeedClientAuth(), is(true));
        assertThat(sslEngine.getWantClientAuth(), is(false));
        
        String value = randomCapitalization(SslClientAuthenticationMode.REQUIRED);
        Settings settings = Settings.builder().put("xpack.security.transport.ssl.client_authentication", value).build();
        try (MockTransportService service = buildService("TS_REQUIRED_CLIENT_AUTH", Version.CURRENT, settings)) {
            TcpTransport originalTransport = (TcpTransport) service.getOriginalTransport();
            try (Transport.Connection connection2 = openConnection(serviceA, service.getLocalNode(), TestProfiles.LIGHT_PROFILE)) {
                sslEngine = getEngineFromAcceptedChannel(originalTransport, connection2);