[autotest] Create ssh tunnel to connect to Chameleond

When Chameleon is in test network, we need to use SSH tunneling to
access its 9992 port.
Chameleon in lab area is not subject to this restriction.

BUG=chromium:521443
TEST=run audio_AudioBasicHeadphone test for Chameleon on test network.

Change-Id: I2ea271bf4c779a98c198a529f599a4b0275f9156
Reviewed-on: https://chromium-review.googlesource.com/295022
Reviewed-by: Hung-ying Tyan <tyanh@chromium.org>
Commit-Queue: Cheng-Yi Chiang <cychiang@chromium.org>
Tested-by: Cheng-Yi Chiang <cychiang@chromium.org>
1 file changed