bot_scaling: Refactor usage message types

Refactor resource message types to make it easier to track global and
region usage.  This will introduce a new message type that will allow me
to phase out the current message for one that will support regional
associations.  Smarter, not harder.

Bug: chromium:1087113
Change-Id: I79bd68079a6f6752fe49a1b1d4c4049d121ab758
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/infra/proto/+/2220335
Reviewed-by: Dhanya Ganesh <dhanyaganesh@chromium.org>
Reviewed-by: David Burger <dburger@chromium.org>
Commit-Queue: Mike Nichols <mikenichols@chromium.org>
Tested-by: Mike Nichols <mikenichols@chromium.org>
2 files changed