Restore default source in e2e test.
Restore default source in e2e test.

Also wait for VoE to start up.

TBR=kjellander@webrtc.org
BUG=issue502
TEST=audio_e2e_test

Review URL: https://webrtc-codereview.appspot.com/643006

git-svn-id: 917f5d3ca488f358c4d40eaec14422cf392ccec9@2391 4adac7df-926f-26a2-2b94-8c16560cd09d

mwgoldsmith/ilbc,mwgoldsmith/libilbc,ShiftMediaProject/libilbc,ShiftMediaProject/libilbc,TimothyGu/libilbc,ShiftMediaProject/libilbc,mwgoldsmith/libilbc,mwgoldsmith/ilbc,ShiftMediaProject/libilbc,ShiftMediaProject/libilbc,mwgoldsmith/ilbc,mwgoldsmith/libilbc,mwgoldsmith/libilbc,mwgoldsmith/ilbc,TimothyGu/libilbc,TimothyGu/libilbc,TimothyGu/libilbc,TimothyGu/libilbc