Re-enable rampup_tests.cc for Android.

BUG=3770
R=pbos@webrtc.org

Review URL: https://webrtc-codereview.appspot.com/27499004

git-svn-id: http://webrtc.googlecode.com/svn/trunk@7180 4adac7df-926f-26a2-2b94-8c16560cd09d