Android: Stop using VideoRenderer class

This CL updates the WebRTC code to stop using the old VideoRenderer and
VideoRenderer.I420Frame classes and instead use the new VideoSink and
VideoFrame classes.

This CL is the first step and the old classes are still left in the code
for now to keep backwards compatibility.

Bug: webrtc:9181
Change-Id: Ib0caa18cbaa2758b7859e850ddcaba003cfb06d6
Reviewed-on: https://webrtc-review.googlesource.com/71662
Reviewed-by: Sami Kalliomäki <sakal@webrtc.org>
Commit-Queue: Magnus Jedvert <magjed@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#22989}

sdk/android/api/org/webrtc/VideoRenderer.java

@@ -195,10 +195,6 @@ public class VideoRenderer {
     }
   }
 
-  // Helper native function to do a video frame plane copying.
-  static native void nativeCopyPlane(
-      ByteBuffer src, int width, int height, int srcStride, ByteBuffer dst, int dstStride);
-
   /** The real meat of VideoSinkInterface. */
   public static interface Callbacks {
     // |frame| might have pending rotation and implementation of Callbacks