[Elastic Agent] empty downloads folder when providing --path.home

[simitt]

When running the docker container and providing --path.home the downloads folder is empty.

Reproduce:

• change docker entrypoint to exec {{ .BeatName }} container --path.home ${HOME_PATH} "$@"
• run cloud command

docker run -it \
  --env HOME_PATH=/app \
  -v <your-path>/app:/app <image-ID>

• Run ls -la <your-path>/app/data/elastic-agent*/downloads; it only shows filebeat and metricbeat (after they have been downloaded by the agent); compare to downloads folder when exec into the docker container, which shows filebeat, metricbeat, heartbeat, endpoint-security, apm-server.

This is required for the elastic cloud setup, as a home path needs to be provided, and the apm-server needs to be bundled.

I have not checked whether this also occurs with another installation method.

cc @ruflin @michalpristas

[elasticmachine]

Pinging @elastic/agent (Team:Agent)