In order to support android, we need to build the Android Webrtc codebase with our necessary changes (to facilitate an IL2cpp compatible interface). In order to do this, the differences from the webrtc-uwp and webrtc codebases must be reconciled. Since that work will need to be done in the future (when webrtc-uwp and webrtc decide to merge, assuming they do), we've opted to not do that work now.
TL;DR: Unity Android/IOS support isn't functional at this time, as there isn't an easy way to apply the uwp changesets that modify the plugin api to the android/ios codebase.
In order to support android, we need to build the Android Webrtc codebase with our necessary changes (to facilitate an IL2cpp compatible interface). In order to do this, the differences from the webrtc-uwp and webrtc codebases must be reconciled. Since that work will need to be done in the future (when webrtc-uwp and webrtc decide to merge, assuming they do), we've opted to not do that work now.
TL;DR: Unity Android/IOS support isn't functional at this time, as there isn't an easy way to apply the uwp changesets that modify the plugin api to the android/ios codebase.