AudioCodingModuleTest.TwoWayCommunication: Remove non-automatic mode

The tests only use the automatic mode, and I'd rather not maintain
(and test!) the rest.

Bug: webrtc:8396
Change-Id: I4cd1096e088d2ea8807a605b8448bd44ff9e88ed
Reviewed-on: https://webrtc-review.googlesource.com/102060
Reviewed-by: Ivo Creusen <ivoc@webrtc.org>
Commit-Queue: Karl Wiberg <kwiberg@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#24852}
diff --git a/modules/audio_coding/test/Tester.cc b/modules/audio_coding/test/Tester.cc
index b064225..4b15fcb 100644
--- a/modules/audio_coding/test/Tester.cc
+++ b/modules/audio_coding/test/Tester.cc
@@ -66,7 +66,7 @@
 #else
 TEST(AudioCodingModuleTest, TwoWayCommunication) {
 #endif
-  webrtc::TwoWayCommunication(ACM_TEST_MODE).Perform();
+  webrtc::TwoWayCommunication().Perform();
 }
 #endif