Metrics: Added load average to system sampling

Closed Gabriel Mazetto requested to merge patch/load_average into master

What does this MR do?

Adds system load average to the sampling metrics

Are there points in the code the reviewer needs to double check?

Grafana import (outsite file)

Why was this MR needed?

This is useful for make correlations with current metrics and system load. We are using it for Geo to get a better picture.

What are the relevant issue numbers?


Screenshots (if relevant)


Grafana JSON to import System Statistics Dashboard System_Statistics-1463794593151.json