autotest: Ignore the unknown vendor event error for now.

This happens on guado-kernelnext since the Intel WP2 chip sends us this
unknown event.

BUG=b:141178173
TEST=Test passed with the fix

Change-Id: Ifa677adc778f73e4108f6e35e5f0ae66eca205e6
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/third_party/autotest/+/1825991
Tested-by: Yu Liu <yudiliu@chromium.org>
Reviewed-by: Yoni Shavit <yshavit@chromium.org>
Commit-Queue: Yu Liu <yudiliu@chromium.org>
diff --git a/client/site_tests/bluetooth_AdapterSanity/bluetooth_AdapterSanity.py b/client/site_tests/bluetooth_AdapterSanity/bluetooth_AdapterSanity.py
index afe060f..a326bb9 100644
--- a/client/site_tests/bluetooth_AdapterSanity/bluetooth_AdapterSanity.py
+++ b/client/site_tests/bluetooth_AdapterSanity/bluetooth_AdapterSanity.py
@@ -21,7 +21,8 @@
 
         """
         fail_terms = ['[^a-z]err[^a-z]']
-        ignore_terms = ['RFKILL control', '"Service Changed" characteristic']
+        ignore_terms = ['RFKILL control', '"Service Changed" characteristic',
+                'Unknown Evt ID: 19']
 
         log_cmd = 'grep -i bluetooth /var/log/messages'
         for term in ignore_terms: