faft: Directly install Autotest dependency, not rely on a test

FAFT and PyAuto tests need to install Autotest dependency to client.
Call the install method instead of running a client test which may
confuse the test results.

BUG=chromium-os:36163
TEST=Remove the Autotest directory on the client and run a FAFT test.
CQ-DEPEND=I34578aff8c22800120a3dbbb369e3663acf6b31c

Change-Id: I46f69671d4acd8d701bc23ae30620b3192ff602d
Reviewed-on: https://gerrit.chromium.org/gerrit/37697
Reviewed-by: Mike Truty <truty@chromium.org>
Reviewed-by: Todd Broch <tbroch@chromium.org>
Reviewed-by: Yusuf Mohsinally <mohsinally@google.com>
Commit-Ready: Tom Wai-Hong Tam <waihong@chromium.org>
Tested-by: Tom Wai-Hong Tam <waihong@chromium.org>
3 files changed