Add other testonly QUICHE flags defined by Envoy.

The Envoy platform flags implementation defines a number of custom
testonly flags. In the interest of unifying these implementations, we
should just put them in upstream QUICHE directly.

PiperOrigin-RevId: 572920670
diff --git a/quiche/quic/core/quic_flags_list.h b/quiche/quic/core/quic_flags_list.h
index a38a699..3fd7ec0 100644
--- a/quiche/quic/core/quic_flags_list.h
+++ b/quiche/quic/core/quic_flags_list.h
@@ -8,15 +8,29 @@
 
 QUIC_FLAG(quic_restart_flag_quic_offload_pacing_to_usps2, false)
 // A testonly reloadable flag that will always default to false.
+QUIC_FLAG(quic_reloadable_flag_http2_testonly_default_false, false)
+// A testonly reloadable flag that will always default to false.
 QUIC_FLAG(quic_reloadable_flag_quic_testonly_default_false, false)
 // A testonly reloadable flag that will always default to false.
 QUIC_FLAG(quic_reloadable_flag_spdy_testonly_default_false, false)
 // A testonly reloadable flag that will always default to true.
+QUIC_FLAG(quic_reloadable_flag_http2_testonly_default_true, false)
+// A testonly reloadable flag that will always default to true.
 QUIC_FLAG(quic_reloadable_flag_quic_testonly_default_true, true)
+// A testonly reloadable flag that will always default to true.
+QUIC_FLAG(quic_reloadable_flag_spdy_testonly_default_true, false)
+// A testonly restart flag that will always default to false.
+QUIC_FLAG(quic_restart_flag_http2_testonly_default_false, false)
 // A testonly restart flag that will always default to false.
 QUIC_FLAG(quic_restart_flag_quic_testonly_default_false, false)
+// A testonly restart flag that will always default to false.
+QUIC_FLAG(quic_restart_flag_spdy_testonly_default_false, false)
+// A testonly restart flag that will always default to true.
+QUIC_FLAG(quic_restart_flag_http2_testonly_default_true, false)
 // A testonly restart flag that will always default to true.
 QUIC_FLAG(quic_restart_flag_quic_testonly_default_true, true)
+// A testonly restart flag that will always default to true.
+QUIC_FLAG(quic_restart_flag_spdy_testonly_default_true, false)
 // If enabled and a BSUS connection is received, blocks server connections until SETTINGS frame is received.
 QUIC_FLAG(quic_reloadable_flag_quic_block_until_settings_received_copt, true)
 // If trrue, early return before write control frame in OnCanWrite() if the connection is already closed.