Revert "Revert "AudioFlinger: Keep track of music effect thread ..."

Revert submission 26624467-revert-25712917-SEPJYAPZTA

Reason for revert: b/330202134 fixed with ag/26627359

Reverted changes: /q/submissionid:26624467-revert-25712917-SEPJYAPZTA

Change-Id: I0a43627e18368f3b883e9d3e33d60d679f2920d5
diff --git a/services/audioflinger/AudioFlinger.h b/services/audioflinger/AudioFlinger.h
index 0f75d6e..7c26f72 100644
--- a/services/audioflinger/AudioFlinger.h
+++ b/services/audioflinger/AudioFlinger.h
@@ -373,7 +373,8 @@
             EXCLUDES_AudioFlinger_Mutex;
 
     status_t moveEffectChain_ll(audio_session_t sessionId,
-            IAfPlaybackThread* srcThread, IAfPlaybackThread* dstThread) final
+            IAfPlaybackThread* srcThread, IAfPlaybackThread* dstThread,
+            IAfEffectChain* srcChain = nullptr) final
             REQUIRES(mutex(), audio_utils::ThreadBase_Mutex);
 
     // This is a helper that is called during incoming binder calls.