[media] Reset audio decoder via AudioDecoder::Reset() (#2672)

1. When AdaptiveAudioDecoder() resets |audio_decoder_|, use
audio_decoder_->Reset() to reset |audio_decoder_|.
2. The PR (#2501) does not clean
up |resampler_| and |channel_mixer_|, which causes some tests failed on
ps5. This PR cleans up |resampler_| and |channel_mixer_| in
AdaptiveAudioDecoder::Reset() to fix the
SbPlayerGetAudioConfigurationTest.MultipleSeeks test failures.

b/327229953

(cherry picked from commit d66b09b)

starboard/shared/starboard/player/filter/adaptive_audio_decoder_internal.cc

@@ -146,7 +146,13 @@ void AdaptiveAudioDecoder::Reset() {
   SB_DCHECK(BelongsToCurrentThread());
 
   if (audio_decoder_) {
+<<<<<<< HEAD
     TeardownAudioDecoder();
+=======
+    audio_decoder_->Reset();
+    resampler_.reset();
+    channel_mixer_.reset();
+>>>>>>> d66b09b0522 ([media] Reset audio decoder via AudioDecoder::Reset() (#2672))
   }
   CancelPendingJobs();
   while (!decoded_audios_.empty()) {