Launching Structured Metrics Service

Bug: 1434483, b/294117492
Change-Id: I3c11ecce2de2ec69c16dc6a3604c308b4d216744
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/4787128


Reviewed-by: Jong Ahn <jongahn@chromium.org>
Commit-Queue: Andrew Bregger <andrewbregger@google.com>
Cr-Commit-Position: refs/heads/main@{#1184822}