Expose RTCConfiguration to java JNI and add an option to disable TCP

BUG=4585, 4589
R=glaznev@webrtc.org, juberti@google.com, pthatcher@webrtc.org

Review URL: https://webrtc-codereview.appspot.com/49809004

Cr-Commit-Position: refs/heads/master@{#9125}
7 files changed