Update API for Objective-C RTCDataChannelConfiguration.

BUG=

Review URL: https://codereview.webrtc.org/1616363005

Cr-Commit-Position: refs/heads/master@{#11405}
diff --git a/webrtc/api/api_tests.gyp b/webrtc/api/api_tests.gyp
index f073cea..2c0d684 100644
--- a/webrtc/api/api_tests.gyp
+++ b/webrtc/api/api_tests.gyp
@@ -20,6 +20,7 @@
           ],
           'sources': [
             'objctests/RTCConfigurationTest.mm',
+            'objctests/RTCDataChannelConfigurationTest.mm',
             'objctests/RTCIceCandidateTest.mm',
             'objctests/RTCIceServerTest.mm',
             'objctests/RTCMediaConstraintsTest.mm',