Update audio renderer position before pausing

As part of pausing DefaultAudioSink, its position-related fields are reset. If
the audio timestamp API was in use, this results in falling back to the
getPlaybackHeadPosition API, which (on some devices) can lead to a jump in the
reported position.

Sample the position before pausing instead of after, to avoid this jump.

-------------
Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=189713376

library/core/src/main/java/com/google/android/exoplayer2/audio/MediaCodecAudioRenderer.java

@@ -393,8 +393,8 @@ public class MediaCodecAudioRenderer extends MediaCodecRenderer implements Media
 
   @Override
   protected void onStopped() {
-    audioSink.pause();
     updateCurrentPosition();
+    audioSink.pause();
     super.onStopped();
   }
 

library/core/src/main/java/com/google/android/exoplayer2/audio/SimpleDecoderAudioRenderer.java

@@ -522,8 +522,8 @@ public abstract class SimpleDecoderAudioRenderer extends BaseRenderer implements
 
   @Override
   protected void onStopped() {
-    audioSink.pause();
     updateCurrentPosition();
+    audioSink.pause();
   }
 
   @Override