cbuildbot_config: disable unittests for factory pre-flight configs too

Same as previous commit in here.

BUG=chromium:864873
TEST=None

Change-Id: Ia9163da0b3ea39ec0ae01116709692b6232ea1a0
Reviewed-on: https://chromium-review.googlesource.com/1147145
Reviewed-by: Mike Frysinger <vapier@chromium.org>
Tested-by: Mike Frysinger <vapier@chromium.org>
diff --git a/cbuildbot/cbuildbot_config.py b/cbuildbot/cbuildbot_config.py
index c28bd48..b50f48a 100755
--- a/cbuildbot/cbuildbot_config.py
+++ b/cbuildbot/cbuildbot_config.py
@@ -2005,6 +2005,7 @@
 internal_pfq_branch.add_config('auron-pre-flight-branch',
   master=True,
   vm_tests=None,
+  unittests=False,
   push_overlays=constants.BOTH_OVERLAYS,
   boards=['auron'],
 )
diff --git a/cbuildbot/config_dump.json b/cbuildbot/config_dump.json
index 6dc8a74..d010c68 100644
--- a/cbuildbot/config_dump.json
+++ b/cbuildbot/config_dump.json
@@ -1759,6 +1759,7 @@
         "prebuilts": "private",
         "push_overlays": "both",
         "sync_chrome": true,
+        "unittests": false,
         "useflags": [
             "chrome_internal"
         ],