AudioFlinger: Offload track transition fix

Trigger state changes in OffloadThread on adding a new offload track.

Bug: 12530661
Change-Id: I95b62764c7ac041d470702e86b951f812eb0e70f
diff --git a/services/audioflinger/Threads.h b/services/audioflinger/Threads.h
index 19289d2..9682fa6 100644
--- a/services/audioflinger/Threads.h
+++ b/services/audioflinger/Threads.h
@@ -394,7 +394,7 @@
     virtual     bool        waitingAsyncCallback();
     virtual     bool        waitingAsyncCallback_l();
     virtual     bool        shouldStandby_l();
-
+    virtual     void        onAddNewTrack_l();
 
     // ThreadBase virtuals
     virtual     void        preExit();
@@ -753,6 +753,7 @@
     virtual     bool        waitingAsyncCallback();
     virtual     bool        waitingAsyncCallback_l();
     virtual     bool        shouldStandby_l();
+    virtual     void        onAddNewTrack_l();
 
 private:
                 void        flushHw_l();