This should let you build AppRTCDemo without much effort.
I built WebRTC distribution on 9/6/2014, extracted trunk/talk/examples/android
,
and it is imported to Android Studio.
It is not straightforward to build WebRTC for Android on Mac OS X.
However, it turned out that at the end of the day, you just need a few files to build it on Android.
While this requries almost no effort to build, you need:
local.properties