Fix memory leak in NativeToJavaVideoFrame.

This method used to just wrap frame when passed a native frame and
create a new one when passed non-native frame. This caused a memory
leak when a new frame was returned because the caller didn't release
the frame. Now the method always returns a new frame and the caller is
responsible for releasing it.

Bug: webrtc:8892, b/72675429
Change-Id: I06d67a6ed4c059cae1d709c51b0266f9c72fef1a
Reviewed-on: https://webrtc-review.googlesource.com/53840
Reviewed-by: Anders Carlsson <andersc@webrtc.org>
Commit-Queue: Sami Kalliomäki <sakal@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#22033}

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

@@ -177,6 +177,7 @@ public class VideoFrame {
     buffer.retain();
   }
 
+  @CalledByNative
   public void release() {
     buffer.release();
   }