common.proto: Use Path in UploadedArtifactsByService

The only consumer of the proto is recipes.  Cq-Depend the change that
makes recipes work with either.

BUG=b:177906602
TEST=generate

Cq-Depend: chromium:2644753
Change-Id: I013dc07357b6e682c9822c30c86e34359f11c581
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/infra/proto/+/2645379
Commit-Queue: LaMont Jones <lamontjones@chromium.org>
Reviewed-by: Alex Klein <saklein@chromium.org>
2 files changed