Conditionalize testing of QUIC server padding.

When the client requests padding and server enables support for padding, it
should work unless QUICHE's version of boringssl is too old to support it.

PiperOrigin-RevId: 929244364

quiche/quic/core/http/end_to_end_test.cc

diff --git a/quiche/quic/core/http/end_to_end_test.cc b/quiche/quic/core/http/end_to_end_test.cc
index 9a949bb..b4bdc1d 100644
--- a/quiche/quic/core/http/end_to_end_test.cc
+++ b/quiche/quic/core/http/end_to_end_test.cc
@@ -9072,7 +9072,10 @@
   const QuicCryptoClientStream* client_crypto_stream =
       static_cast<const QuicCryptoClientStream*>(
           GetClientSession()->GetCryptoStream());
+
+#if BORINGSSL_API_VERSION >= 41
   EXPECT_TRUE(client_crypto_stream->ServerPaddingSentForTesting());
+#endif
 
   client_->Disconnect();
 }