Initialize session in quic_simple_server_stream_test.

The test spdy session should be initialized to reflect the correct number of HTTP/3 unidirectional streams.

gfe-relnote: test change only, not protected.
PiperOrigin-RevId: 262949415
Change-Id: I5f06ec8e132a485698790abe587c4344bedc6361
diff --git a/quic/tools/quic_simple_server_stream_test.cc b/quic/tools/quic_simple_server_stream_test.cc
index b53f9d0..bf435b9 100644
--- a/quic/tools/quic_simple_server_stream_test.cc
+++ b/quic/tools/quic_simple_server_stream_test.cc
@@ -204,6 +204,7 @@
         kInitialStreamFlowControlWindowForTest);
     session_.config()->SetInitialSessionFlowControlWindowToSend(
         kInitialSessionFlowControlWindowForTest);
+    session_.Initialize();
     stream_ = new StrictMock<TestStream>(
         GetNthClientInitiatedBidirectionalStreamId(
             connection_->transport_version(), 0),
@@ -416,7 +417,7 @@
   // Create a new promised stream with even id().
   auto promised_stream = new StrictMock<TestStream>(
       GetNthServerInitiatedUnidirectionalStreamId(
-          connection_->transport_version(), 0),
+          connection_->transport_version(), 1),
       &session_, WRITE_UNIDIRECTIONAL, &memory_cache_backend_);
   session_.ActivateStream(QuicWrapUnique(promised_stream));