[autotest] Restrict chameleon_audio on audio_box

As our first priority is to stablize chameleon_audio test suite on the
two audio boxes, this CL restrict chameleon_audio test suite on
audio_box so we can stop issue tracker from filing bugs for other
nonstable boards.

BUG=None
TEST=None

Change-Id: Ie43378323f654aa650d09565f9e6f3b92ff3f7f0
Reviewed-on: https://chromium-review.googlesource.com/286327
Reviewed-by: Wai-Hong Tam <waihong@chromium.org>
Commit-Queue: Cheng-Yi Chiang <cychiang@chromium.org>
Tested-by: Cheng-Yi Chiang <cychiang@chromium.org>
1 file changed