Adding Media.VideoCapture.Device.Opened.ByModelId metric

The following change is to create a sparse histogram to identify web camera models used in Chrome (starting with macOS). Here, we are mapping the USB ID (model_id) to an unsigned integer.

Change-Id: I5688be0dd79aedbdfca60edfcb19131dc6711c60
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/4552857


Commit-Queue: Angelo Tadres <atadres@chromium.org>
Reviewed-by: Mark Foltz <mfoltz@chromium.org>
Reviewed-by: Robert Kaplow <rkaplow@chromium.org>
Reviewed-by: Evan Liu <evliu@google.com>
Cr-Commit-Position: refs/heads/main@{#1149421}