request help: How do I pass the values created by the runner filter to the next plugin?

### Issue description
My final goal is to put variables created in the runner plugin into the elastic logger.

ex)
step1. make variable in runner plugin and pass variable to next plugin
`@Override
public void filter(HttpRequest request, HttpResponse response, PluginFilterChain chain) {
String test_value = "bar";
chain.filter(request, response);
}`

step2. Business logic is executed through the variable (test_value) passed from the plug-in in the next step.

step3. The passed variables are finally recorded in the elastic logger.
`curl http://127.0.0.1:9180/apisix/admin/plugin_metadata/elasticsearch-logger \
-H 'X-API-KEY: edd1c9f034335f136f87ad84b625c8f1' -X PUT -d '
{
"log_format": {
"foo": "$test_value"
}
}'`

I want to know how to pass the created variable (header value?) and record it in the logger.

### Environment

* your apisix-java-plugin-runner version = 3.0