Introducing MEET_DEVICE form factor for Finch Dashboard

There is need for a meet__device form factor to aid in accurately
determining the effected percent of the devices in the fleet a specific
flinch flag might be affecting.

Bug: b/247115676
Test: Built and deployed chromium
Low-Coverage-Reason: outside scope of CL
Change-Id: Ic82268499e9497e9f13c5ab7fa0520a4ba60f410
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/3963213
Reviewed-by: Alexei Svitkine <asvitkine@chromium.org>
Reviewed-by: Justin Donnelly <jdonnelly@chromium.org>
Commit-Queue: Joshua Pius <joshuapius@google.com>
Reviewed-by: Ilya Sherman <isherman@chromium.org>
Cr-Commit-Position: refs/heads/main@{#1072800}