[autotest] Do not enforce minimum available duts check for certain conditions

1. suite name is not in the white list defined in global config.
2. Autotest instance is not in lab, e.g., local setup or moblab.
3. Total number of all duts are less than the minimum requirement.

BUG=chromium:377063,chromium:377083
TEST=run_suite against local and cauotest instance, make sure all 3 conditions
are covered.

Change-Id: I7d2865e173a7bafc373cb4d08fa27d969b6cd79f
Reviewed-on: https://chromium-review.googlesource.com/201425
Commit-Queue: Dan Shi <dshi@chromium.org>
Tested-by: Dan Shi <dshi@chromium.org>
Reviewed-by: Simran Basi <sbasi@chromium.org>
4 files changed