Enable autotest suite scheduler to support flashing multiple boards and multiple targets.


I have a testbed that requires different types of boards. Both of which are android. Currently we only support one board flashing at a time but we need support for a CL like this:

https://chrome-internal-review.googlesource.com/#/c/305457/1/puppet/modules/lab/files/autotest_cautotest/suite_scheduler.ini