This allows other tests using RTC stats to get pretty printing as well. Bug: webrtc:381524905 Change-Id: Ib1eb9e1dad36b89e5b1c2ec687fcfeb308f82939 Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/370761 Reviewed-by: Evan Shrubsole <eshr@webrtc.org> Reviewed-by: Henrik Boström <hbos@webrtc.org> Reviewed-by: Harald Alvestrand <hta@webrtc.org> Commit-Queue: Evan Shrubsole <eshr@webrtc.org> Cr-Commit-Position: refs/heads/main@{#43575}