Remove calls to deprecated CreatePC() and CreateDC()

Anything linking to //third_party/jsoncpp is hiding deprecated usage
warnings, so these were not discovered earlier.

Bug: chromium:983223
Change-Id: Id0ade4ca016f19db16377dbeeb756358a7e94fa2
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/258124
Reviewed-by: Harald Alvestrand <hta@webrtc.org>
Auto-Submit: Florent Castelli <orphis@webrtc.org>
Commit-Queue: Florent Castelli <orphis@webrtc.org>
Cr-Commit-Position: refs/heads/main@{#36463}
diff --git a/pc/test/integration_test_helpers.h b/pc/test/integration_test_helpers.h
index 78c91af..c35c357 100644
--- a/pc/test/integration_test_helpers.h
+++ b/pc/test/integration_test_helpers.h
@@ -410,7 +410,9 @@
 
   void CreateDataChannel(const std::string& label,
                          const webrtc::DataChannelInit* init) {
-    data_channels_.push_back(pc()->CreateDataChannel(label, init));
+    auto data_channel_or_error = pc()->CreateDataChannelOrError(label, init);
+    ASSERT_TRUE(data_channel_or_error.ok());
+    data_channels_.push_back(data_channel_or_error.MoveValue());
     ASSERT_TRUE(data_channels_.back().get() != nullptr);
     data_observers_.push_back(
         std::make_unique<MockDataChannelObserver>(data_channels_.back()));
@@ -825,8 +827,11 @@
     modified_config.set_cpu_adaptation(false);
 
     dependencies.observer = this;
-    return peer_connection_factory_->CreatePeerConnection(
-        modified_config, std::move(dependencies));
+    auto peer_connection_or_error =
+        peer_connection_factory_->CreatePeerConnectionOrError(
+            modified_config, std::move(dependencies));
+    return peer_connection_or_error.ok() ? peer_connection_or_error.MoveValue()
+                                         : nullptr;
   }
 
   void set_signaling_message_receiver(