devinstall_test: Use 10.0.2.2 as binhost's IP

Avoid a conflict between qemu's networking and the host's IP address
when the latter happens to be in the 10.0.2.* range. The dev_install
requests from the guest to, say 10.0.2.219, were handled by qemu itself
and not actually passed to the host.

Forcing the guest to send requests to 10.0.2.2 instead will now ensure
that it always points to the host.
https://wiki.qemu.org/Documentation/Networking#User_Networking_.28SLIRP.29

Note: existing cros lint errors not fixed

BUG=chromium:808045
TEST=cros tryjob --swarming novato-release-tryjob
TEST=cros tryjob novato-release-tryjob
TEST=local test on novato image ./devmode-test/devinstall_test.py ...

Change-Id: I9d5873a4820c10156f7046e04b348b7561a9befd
Reviewed-on: https://chromium-review.googlesource.com/947042
Commit-Ready: Nicolas Norvez <norvez@chromium.org>
Tested-by: Nicolas Norvez <norvez@chromium.org>
Reviewed-by: Don Garrett <dgarrett@chromium.org>
1 file changed