Add InstanceId dimension, when available

When available in the gerrit configuration, metrics are hydrated with
the InstanceId, so that the behaviour of a specific instance can be
observed within a cluster of gerrit instances.

Feature: Issue 13217
Change-Id: I963f52b6f491b7fd84ff227d68fca19ec85138db
5 files changed
tree: 84aaa51771c1c08a9d2d6b5c9d11223810371ea2
  1. src/
  2. BUILD
  3. external_plugin_deps.bzl