Lower the priority of QAV suite to DEFAULT.

TEST=Trybot
BUG=chromium:366201

Change-Id: I6f20e4eb1ab07f86e6f1a000b47293d031066e2d
Reviewed-on: https://chromium-review.googlesource.com/196695
Commit-Queue: Prashanth B <beeps@chromium.org>
Tested-by: Prashanth B <beeps@chromium.org>
Reviewed-by: Yu-Ju Hong <yjhong@chromium.org>
diff --git a/buildbot/cbuildbot_config.py b/buildbot/cbuildbot_config.py
index 025b5a3..fe912a9 100755
--- a/buildbot/cbuildbot_config.py
+++ b/buildbot/cbuildbot_config.py
@@ -577,6 +577,7 @@
 
     qav_kwargs = kwargs.copy()
     qav_kwargs.update(qav_dict)
+    qav_kwargs['priority'] = constants.HWTEST_DEFAULT_PRIORITY
 
     # BVT + AU suite.
     return [cls(cls.DEFAULT_HW_TEST, **kwargs),