Add a few functions to android test application

1. Add playing ringtone
2. Add receiving headset plug intent
3. Add a runnable to simulate cpu load

BUG=
TEST=trybot
Review URL: https://webrtc-codereview.appspot.com/858007

git-svn-id: http://webrtc.googlecode.com/svn/trunk@2892 4adac7df-926f-26a2-2b94-8c16560cd09d
5 files changed