Disable flaky test MultiThreadedCertVerifierTest.CancelRequest

BUG=171812
NOTRY=true

Review URL: https://chromiumcodereview.appspot.com/12047060

git-svn-id: http://src.chromium.org/svn/trunk/src/build@178428 4ff67af0-8c30-449e-8e8b-ad334ec8d88c

android/pylib/gtest/filter/net_unittests_disabled

@@ -11,6 +11,9 @@ HTTPSEVCRLSetTest.FreshCRLSet
 HTTPSRequestTest.ClientAuthTest
 HTTPSRequestTest.ResumeTest
 HTTPSRequestTest.SSLSessionCacheShardTest
+# Bug: 171812
+MultiThreadedCertVerifierTest.CancelRequest
+
 PythonUtils.PythonRunTime
 TransportSecurityStateTest.ValidPinsHeadersSHA1
 TransportSecurityStateTest.ValidPinsHeadersSHA256