Re-enable the P2PTransportChannelMultihomedTest.TestBasic

BUG=webrtc:2409

Review-Url: https://codereview.webrtc.org/2485963002
Cr-Original-Commit-Position: refs/heads/master@{#15030}
Cr-Mirrored-From: https://chromium.googlesource.com/external/webrtc
Cr-Mirrored-Commit: a3095d001b195beac903fc47de28dc30357eaf51
1 file changed