Have the test code get the original connection ID from the client instead of the server, to avoid a race condition with the server thread.

Regular and TSAN tests pass.

PiperOrigin-RevId: 449042361
diff --git a/quiche/quic/core/http/end_to_end_test.cc b/quiche/quic/core/http/end_to_end_test.cc
index 37e302e..562b032 100644
--- a/quiche/quic/core/http/end_to_end_test.cc
+++ b/quiche/quic/core/http/end_to_end_test.cc
@@ -6002,7 +6002,7 @@
   // Parse the saved packet to make sure it's valid.
   SimpleQuicFramer validation_framer({version_});
   validation_framer.framer()->SetInitialObfuscators(
-      GetServerConnection()->GetOriginalDestinationConnectionId());
+      GetClientConnection()->GetOriginalDestinationConnectionId());
   ASSERT_GT(copying_writer->packets().size(), 0u);
   EXPECT_TRUE(validation_framer.ProcessPacket(*copying_writer->packets()[0]));
   // TODO(dschinazi) figure out a way to use a MockRandom in this test so we