public void setUserAgent(final String userAgent) {
        this.userAgent = userAgent;
    }
Sets custom User-Agent HTTP header.

@param userAgent Custom User-Agent.

@see ManagedChannelBuilder#userAgent(String)
grpc-client-spring-boot-starter/src/main/java/net/devh/boot/grpc/client/config/GrpcChannelProperties.java