merge-into-chromeos: Exclude dry runs from previous merge commits
merge-into-chromeos: Exclude dry runs from previous merge commits

Otherwise we end up with this: https://crrev.com/c/3422185

BUG=None
TEST=None

Change-Id: I8abd0e3f4465e9ae2ae34630dde5a3b15e190b09
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/crosvm/+/3421734
Reviewed-by: Daniel Verkamp <72bc170b46ec491f7bdd4359a1c0bfed274de40c@chromium.org>
Tested-by: kokoro <2ac7b1f3fa578934c95181d4272be0d3bca00121@google.com>

google/crosvm,google/crosvm,google/crosvm,google/crosvm