Fix a bug where all wrapped codecs were considered software codecs.

This is not the case for fallback codecs.

Bug: webrtc:7925
Change-Id: I5039d8879923a2db1e7c08bb5640763dd20ea8e7
Reviewed-on: https://webrtc-review.googlesource.com/24863
Commit-Queue: Sami Kalliomäki <sakal@webrtc.org>
Reviewed-by: Magnus Jedvert <magjed@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#20861}

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

@@ -27,5 +27,10 @@ public class VideoEncoderFallback extends WrappedNativeVideoEncoder {
     return createNativeEncoder(fallback, primary);
   }
 
+  @Override
+  boolean isSoftwareEncoder() {
+    return isWrappedSoftwareEncoder(primary);
+  }
+
   private static native long createNativeEncoder(VideoEncoder fallback, VideoEncoder primary);
 }