Backport of docs: clarify the behavior of prepending hostname to metrics into release/1.14.x#17579

hc-github-team-consul-core wants to merge 2 commits intorelease/1.14.xhashicorp/consul:release/1.14.xfrom

backport/gh-17320-update-metrics-doc/probably-promoted-lynxhashicorp/consul:backport/gh-17320-update-metrics-doc/probably-promoted-lynxCopy head branch name to clipboard