Remove webrtc::VideoDecoder::PrefersLateDecoding.

This is just general cleanup.

The assumed behavior is late decoding, and this function is not used to make any decision (except in the deprecated jitter buffer).

Bug: webrtc:12271
Change-Id: Ifb48186d55903f068f25e44c5f73e7a724f6f456
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/200804
Commit-Queue: Philip Eliasson <philipel@webrtc.org>
Reviewed-by: Sami Kalliomäki <sakal@webrtc.org>
Reviewed-by: Christoffer Rodbro <crodbro@webrtc.org>
Reviewed-by: Erik Språng <sprang@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#32940}

sdk/android/src/java/org/webrtc/AndroidVideoDecoder.java

@@ -291,11 +291,6 @@ class AndroidVideoDecoder implements VideoDecoder, VideoSink {
     return VideoCodecStatus.OK;
   }
 
-  @Override
-  public boolean getPrefersLateDecoding() {
-    return true;
-  }
-
   @Override
   public String getImplementationName() {
     return codecName;