[autotest] Delete only the installed client dir on machine_install

* Moblab has server code installed in /usr/local/autotest.
* Autotest normally installs client/ code in /usr/local/autotest on
  normal DUTs but on Moblab installs in /usr/local/autodir.
* The old code here deleted ['/usr/local/autotest', '/usr/local/autodir']
  always. Therefore on Moblab, it breaks the running scheduler and etc
  processes.
* We want it here to delete only the correct installed autotest client
  directory, therefore the autotest.Autotest.get_installed_autodir will
  find this directory out of the list of ['/usr/local/autotest',
  '/usr/local/autodir'].
* Therefore on Moblab only /usr/local/autodir is deleted not
  /usr/local/autotest

Also added the moblab-scheduler-init process to be checked for when
running verify.

BUG=chromium:409154
TEST=Ran a suite locally on my moblab against a peppy DUT. Also tested
against a Moblab DUT installed in the lab via a local scheduler.

Change-Id: I3752276e35b23e1194a4d110127ec52de7c534e2
Reviewed-on: https://chromium-review.googlesource.com/215845
Reviewed-by: Dan Shi <dshi@chromium.org>
Tested-by: Simran Basi <sbasi@chromium.org>
Commit-Queue: Simran Basi <sbasi@chromium.org>
2 files changed