Include metadata metric

[JeffLuoo]

What would you like to be added:

A metadata metric which includes the following information:

• Version of the EPP
• Git Hash of Build

Why is this needed:

When we look at the metrics like latency in dashboard, we can use the metadata metric to filter by a specific version and then align the timestamp with other metrics like latency to compare metrics data between EPP versions.

[JeffLuoo]

Please add other metadata you think might be needed.