[Metricbeat] Reintroduce the size flag to docker.container

[mtojek]

As the "size" flag change (#14979) has been reverted in #16600 due to a timeout issue for some dockerd versions (around 1.13), it's time to reintroduce it again, but in a different way. Some ideas:

1. Consider creating a new metricset which enables call with "size" flag enabled.
2. Make "size" flag optional.

[botelastic]

This issue has been automatically marked as stale because it has not had recent activity. It will be closed if no further activity occurs. Thank you for your contributions.

[sundarv85]

I'm having this issue where the root_fs and rw are 0 and I see this was fixed and reverted back - with this new issue now opened.

Will this be fixed?

[gizas]

Re-openning and re-assigning issue in order to be prioritised accordingly.

Issue was observed for:
Metricbeat 8.9 along with Docker module
Docker 20.10.23, build 7155243 Docker Host running on Amazon 2 Linux-ECS

[PeterPaulH]

In reply to the above remark: We run metricbeat 8.10.2 and observe this issue

[PeterPaulH]

We still observe this issue in 8.13