bot_scaling.proto: Add SwarmingDimension message type

Add a SwarmingDimension message type, as a repeating field, in the
BotPolicy message, that will be utilized to validate the current
Swarming allocation prior to triggering an additional adjustment.  The
intention is to ensure that the last configuration is in place before
triggering any type of further adjustment.

Bug: chromium:1053818
Change-Id: I2890b79e29a439dd07919ca4dbd8d50cae086798
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/infra/proto/+/2062737
Commit-Queue: Mike Nichols <mikenichols@chromium.org>
Tested-by: Mike Nichols <mikenichols@chromium.org>
Reviewed-by: Dhanya Ganesh <dhanyaganesh@chromium.org>
3 files changed