public void addHandler(ServerServiceDefinition definition) {
        log.info("Bind handler {} into gRPC server {}:{}", definition.getClass().getSimpleName(), host, port);
        nettyServerBuilder.addService(definition);
    }
Require for `server.crt` and `server.pem` for open ssl at server side.

@param certChainFile  `server.crt` file
@param privateKeyFile `server.pem` file
oap-server/server-library/library-server/src/main/java/org/apache/skywalking/oap/server/library/server/grpc/GRPCServer.java