Retrieving integration configuration for auto-discovered inputs on kubernetes

**Describe the enhancement:**
With beats, the configuration was available to metricbeat and filebeat locally on host but with agent and packages we moved the configuration definition in package registry. So when Kubernetest discovers that pod runs a software that we monitor, either through dynamic inputs conditionals in agent config or via hints based discovery, agent needs to download the integration config for the auto-discovered software. When we deliver this enhancement, agent will automagically ship data to right datastreams in elasticsearch similar to how beats do today. The user still needs to install the right package in kibana. We will tackle the auto-installation of package in separate issue.

Example scenario:
Worker node is running nginx on pod and through dynamic inputs or hints based auto-discovery, agent detects the existence of nginx running on that worker node. Agent is able to retrieve the nginx configuration for metrics and logs, fill in the values provided in auto-discovery configuration -( e.g see configuration examples in metricbeat [here](https://www.elastic.co/guide/en/beats/metricbeat/current/configuration-autodiscover.html) and is able to ship data to elasticsearch successfully.