Removes C++20-style designated initializers from nghttp2_adapter_test.cc.

PiperOrigin-RevId: 442932673
diff --git a/quiche/http2/adapter/nghttp2_adapter_test.cc b/quiche/http2/adapter/nghttp2_adapter_test.cc
index f542429..f6bf097 100644
--- a/quiche/http2/adapter/nghttp2_adapter_test.cc
+++ b/quiche/http2/adapter/nghttp2_adapter_test.cc
@@ -1778,7 +1778,7 @@
 
   const std::string initial_frames =
       TestFrameSequence()
-          .ServerPreface({{.id = MAX_CONCURRENT_STREAMS, .value = 1}})
+          .ServerPreface({{MAX_CONCURRENT_STREAMS, 1}})
           .Serialize();
 
   // Server preface (SETTINGS with MAX_CONCURRENT_STREAMS)
@@ -2612,7 +2612,7 @@
 
   const std::string initial_frames =
       TestFrameSequence()
-          .ServerPreface({{.id = MAX_CONCURRENT_STREAMS, .value = 1}})
+          .ServerPreface({{MAX_CONCURRENT_STREAMS, 1}})
           .Serialize();
   testing::InSequence s;