Revert r6358 "AppRTCDemo(Android): only stop the cameraThread's looper after stopping the camera."

Makes stopping flakier for some reason :/

BUG=
R=glaznev@webrtc.org

Review URL: https://webrtc-codereview.appspot.com/21609004

git-svn-id: http://webrtc.googlecode.com/svn/trunk@6361 4adac7df-926f-26a2-2b94-8c16560cd09d