[cronet] Fix BidirectionalStreamQuicTest#testStreamFailBeforeWriteIsExecutedOnNetworkThread flake

The assertion on quic detail error code is flaky.
Sometimes we get QUIC_PACKET_READ_ERROR.
The test is meant to test that there is no crash.
The detail error information is not crucial. This test removes it.

Bug: 746575
Change-Id: I53800ee57aced2cd5aa22d67d39de022f47ac9ce
Reviewed-on: https://chromium-review.googlesource.com/580533Reviewed-by: Miriam Gershenson <mgersh@chromium.org>
Commit-Queue: Helen Li <xunjieli@chromium.org>
Cr-Commit-Position: refs/heads/master@{#488438}

components/cronet/android/test/javatests/src/org/chromium/net/BidirectionalStreamQuicTest.java

@@ -336,9 +336,6 @@ public class BidirectionalStreamQuicTest extends CronetTestBase {
                 || NetError.ERR_CONNECTION_REFUSED == networkError.getCronetInternalErrorCode());
         if (NetError.ERR_CONNECTION_REFUSED == networkError.getCronetInternalErrorCode()) return;
         assertTrue(callback.mError instanceof QuicException);
-        QuicException quicException = (QuicException) callback.mError;
-        // 16 is QUIC_PEER_GOING_AWAY
-        assertEquals(16, quicException.getQuicDetailedErrorCode());
     }
 
     @SmallTest