Try use Java Bindings Library

Based on the 2 files that where missing from the jars in the Google
WebRTC build script (they are compiled into the WebRTC application
itself) not as a jar).
I manually created a new jar file called ViEAndroidJavaAPI.jar.
This was created on the Ubuntu machine using the following command

XXX@ubuntu:~/WebRTCDemo/trunk/webrtc/video_engine/test/android/bin/classes$
jar cvf ViEAndroidJavaAPI.jar
org/webrtc/videoengineapp/IViEAndroidCallback.class
org/webrtc/videoengineapp/ViEAndroidJavaAPI.class
added manifest
adding: org/webrtc/videoengineapp/IViEAndroidCallback.class(in = 218)
(out= 173)(deflated 20%)
adding: org/webrtc/videoengineapp/ViEAndroidJavaAPI.class(in = 2845)
(out= 1303)(deflated 54%)

Then a new Java Bindings Library project was added to the solution. The
jar was added to the new project and the references updated to point to
the new project instead of the old manual c# file
Adding a reference to System.Xml
Fixing build warnings

Fixing build warnings related to
Type implements Android.Runtime.IJavaObject but does not inherit from
Java.Lang.Object.
Renaming the Java Binding Library

- renaming the java binding library to match the actual package name in
java for consistency
- adding the jar in the java bindings library also to the app as per the
answer found here in the first answer
(http://stackoverflow.com/questions/10911214/monodroid-issue-with-jar-binding-zubhium-sdk)
Replacing all jar classes with JBL

Excluding all the converted Java -> C# classes this is never going to
work since there are specific calls in the C++ code that is requiring
Java classes it seems. So moving to JBL for all classes except the main
Activity.
Adding the jars to the main project as well.
Changing namespaces to handle the new changes
App is running, all screens seems to be working except actuall making a
video call