Consult session instead of crypto_stream on whether encryption is established in QBONE sessions as the former can be overridden to incorporate other signals.

PiperOrigin-RevId: 419903799
diff --git a/quic/qbone/qbone_session_base.cc b/quic/qbone/qbone_session_base.cc
index 2f2f31e..2b3f295 100644
--- a/quic/qbone/qbone_session_base.cc
+++ b/quic/qbone/qbone_session_base.cc
@@ -108,7 +108,7 @@
 
 std::unique_ptr<QuicStream> QboneSessionBase::CreateDataStream(
     QuicStreamId id) {
-  if (crypto_stream_ == nullptr || !crypto_stream_->encryption_established()) {
+  if (!IsEncryptionEstablished()) {
     // Encryption not active so no stream created
     return nullptr;
   }