add universal_newlines=True in KillADB()

This fixes https://console.cloud.google.com/errors/CLH79JmVktryMg?time=P1D&project=chromium-swarm-dev

Bug: 1198820
Change-Id: Id4041a93f17ef5d513b5e7587d051883d37b6fef
Reviewed-on: https://chromium-review.googlesource.com/c/infra/luci/python-adb/+/2936244
Auto-Submit: Junji Watanabe <jwata@google.com>
Commit-Queue: Takuto Ikuta <tikuta@chromium.org>
Reviewed-by: Takuto Ikuta <tikuta@chromium.org>
1 file changed