Improve ALS Functional Test

Add a subtest mode to accept specific luminescence range.
Make subtests run in sequence instead of in parallel.
Modify UI to allow display operator instruction for each subtest.
Allow subtest list to be passed in.

BUG=chromium-os-partner:6615
TEST=pass all subtests, tested subtest time-out, see UI changes

Change-Id: I212ca96b669c9ba69f0a0bc395e0f648e229f1a1
Reviewed-on: https://gerrit.chromium.org/gerrit/12674
Reviewed-by: Dave Parker <dparker@chromium.org>
Commit-Ready: Vic Yang <victoryang@chromium.org>
Tested-by: Vic Yang <victoryang@chromium.org>
2 files changed