Remove incorrect uses of GetHeadersStreamId().

Many places call GetHeadersStreamId() only to use the first stream id. So I
reaplced them with GetFirstBirectionalStreamId().

gfe-relnote: v99 and test change only, not protected.
PiperOrigin-RevId: 261412202
Change-Id: I54f3b5b5a100d8b8d31a0de5ecb324b474c6a430
diff --git a/quic/core/quic_stream_test.cc b/quic/core/quic_stream_test.cc
index ee9676f..d371866 100644
--- a/quic/core/quic_stream_test.cc
+++ b/quic/core/quic_stream_test.cc
@@ -143,9 +143,9 @@
   uint32_t initial_flow_control_window_bytes_;
   QuicTime::Delta zero_;
   ParsedQuicVersionVector supported_versions_;
-  const QuicStreamId kTestStreamId =
-      QuicUtils::GetHeadersStreamId(GetParam().transport_version) +
-      QuicUtils::StreamIdDelta(GetParam().transport_version);
+  QuicStreamId kTestStreamId =
+      GetNthClientInitiatedBidirectionalStreamId(GetParam().transport_version,
+                                                 1);
 };
 
 // Non parameterized QuicStreamTest used for tests that do not