common.proto: Add N2N DeltaType

BUG=chromium:1122854
TEST=regen

Change-Id: I97503e03ef4f22f610c66e5d0ddafad5e66d169d
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/infra/proto/+/2670713
Auto-Submit: George Engelbrecht <engeg@google.com>
Commit-Queue: Jack Neus <jackneus@google.com>
Reviewed-by: Jack Neus <jackneus@google.com>
2 files changed