Andrew Dunham 717d589149 metrics: revert changes to MultiLabelMap's String method
This breaks its ability to be used as an expvar and is blocking a trunkd
deploy. Revert for now, and add a test to ensure that we don't break it
in a future change.

Updates #13550

Signed-off-by: Andrew Dunham <andrew@du.nham.ca>
Change-Id: I1f1221c257c1de47b4bff0597c12f8530736116d
2024-09-25 19:20:50 -04:00
..