Remove ctor for BuiltInNetworkBehaviorConfig

The purpose is to allow parameterized construction.
Ex,
  const webrtc::BuiltInNetworkBehaviorConfig good_network_config = {
      .queue_length_packets = 50,
      .queue_delay_ms = 10,
      .link_capacity_kbps = 5000};

Bug: None
Change-Id: I36b216eea8d1fd69d37f2f9f67a9645a7de2a467
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/207426
Reviewed-by: Artem Titov <titovartem@webrtc.org>
Commit-Queue: Per Kjellander <perkj@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#33270}
diff --git a/api/test/simulated_network.h b/api/test/simulated_network.h
index 3fba61f..fcac51f 100644
--- a/api/test/simulated_network.h
+++ b/api/test/simulated_network.h
@@ -46,8 +46,7 @@
 // for built-in network behavior that will be used by WebRTC if no custom
 // NetworkBehaviorInterface is provided.
 struct BuiltInNetworkBehaviorConfig {
-  BuiltInNetworkBehaviorConfig() {}
-  // Queue length in number of packets.
+  //  Queue length in number of packets.
   size_t queue_length_packets = 0;
   // Delay in addition to capacity induced delay.
   int queue_delay_ms = 0;