AudioService now differentiates BT headsets and car kits.

The BT headset detection now makes the difference between car kits and headsets, which can be used by audio policy manager.
The headset connection is also detected earlier, that is when the headset is connected and not when the SCO socket is connected as it was the case before. This allows the audio policy manager to suspend A2DP output while ringing if a SCO headset is connected.
diff --git a/libs/audioflinger/AudioFlinger.cpp b/libs/audioflinger/AudioFlinger.cpp
index fcf8a79..d019097 100644
--- a/libs/audioflinger/AudioFlinger.cpp
+++ b/libs/audioflinger/AudioFlinger.cpp
@@ -810,7 +810,7 @@
 
 AudioFlinger::PlaybackThread::PlaybackThread(const sp<AudioFlinger>& audioFlinger, AudioStreamOut* output)
     :   ThreadBase(audioFlinger),
-        mMixBuffer(0), mSuspended(false), mBytesWritten(0), mOutput(output),
+        mMixBuffer(0), mSuspended(0), mBytesWritten(0), mOutput(output),
         mLastWriteTime(0), mNumWrites(0), mNumDelayedWrites(0), mInWrite(false)
 {
     readOutputParameters();
diff --git a/libs/audioflinger/AudioFlinger.h b/libs/audioflinger/AudioFlinger.h
index c9f3448..4ba5977 100644
--- a/libs/audioflinger/AudioFlinger.h
+++ b/libs/audioflinger/AudioFlinger.h
@@ -502,8 +502,8 @@
                     AudioStreamOut* getOutput() { return mOutput; }
 
         virtual     int         type() const { return mType; }
-                    void        suspend() { mSuspended = true; }
-                    void        restore() { mSuspended = false; }
+                    void        suspend() { mSuspended++; }
+                    void        restore() { if (mSuspended) mSuspended--; }
         virtual     String8     getParameters(const String8& keys);
         virtual     void        audioConfigChanged(int event, int param = 0);
 
@@ -520,7 +520,7 @@
     protected:
         int                             mType;
         int16_t*                        mMixBuffer;
-        bool                            mSuspended;
+        int                             mSuspended;
         int                             mBytesWritten;
         bool                            mMasterMute;
         SortedVector< wp<Track> >       mActiveTracks;