Allows injection of network controller factory in test fixture.

Bug: webrtc:9155
Change-Id: I929c4cde66ad6743b4a8df2df3abfa7593992977
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/134645
Reviewed-by: Stefan Holmer <stefan@webrtc.org>
Commit-Queue: Sebastian Jansson <srte@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#27843}

test/call_test.cc

@@ -220,6 +220,7 @@ void CallTest::CreateSenderCall(const Call::Config& config) {
   auto sender_config = config;
   sender_config.network_state_predictor_factory =
       network_state_predictor_factory_.get();
+  sender_config.network_controller_factory = network_controller_factory_.get();
   sender_call_.reset(Call::Create(sender_config));
 }