Call AudioMixer only from MixerThread threadLoop.

As part of change:
Remove track name offset by TRACK0.
Move track name management to the Tracks class.
Sync mixer track name to FastMixer track index.

Fixes regression introduced by commit 8ed196a.

Test: SoundPool, AudioTrack CTS, Usability
Bug: 72937362
Bug: 73004420
Change-Id: I2f1a33f6f0da66bcd7aa91e2a4b663ff822df645
diff --git a/services/audioflinger/TrackBase.h b/services/audioflinger/TrackBase.h
index a3ea756..a7e966f 100644
--- a/services/audioflinger/TrackBase.h
+++ b/services/audioflinger/TrackBase.h
@@ -54,6 +54,11 @@
         TYPE_PATCH,
     };
 
+    enum {
+        TRACK_NAME_PENDING = -1,
+        TRACK_NAME_FAILURE = -2,
+    };
+
                         TrackBase(ThreadBase *thread,
                                 const sp<Client>& client,
                                 uint32_t sampleRate,