Add device_label tag in addition to label tag.

[bkabrda]

What does this PR do?

This makes labels a bit more consistent with agent's builtin io check, which uses device_label. When this is merged, users will be able to consistently use device_label tag for metrics from both of these checks.

Motivation

Additional Notes

Review checklist (to be filled by reviewers)

• Feature or bugfix MUST have appropriate tests (unit, integration, e2e)
• PR title must be written as a CHANGELOG entry (see why)
• Files changes must correspond to the primary purpose of the PR as described in the title (small unrelated changes should have their own PR)
• PR must have changelog/ and integration/ labels attached

[bkabrda]

Thanks for the reviews! Merging.