reorganize SoundPool and JetPlayer code.

Reorganize SoundPool and JetPlayer code to be ready for the
creation of libmedia_native.

Split SoundPool between libsoundpool (JNI) and libmedia(sound pool implementation).
Remove dependencies on nativehelper/jni.h from JetPlayer.

Change-Id: I130c6014173b714329929dd82c5dfb70b757a610
diff --git a/media/libmedia/Android.mk b/media/libmedia/Android.mk
index 21e8f29..4cae467 100644
--- a/media/libmedia/Android.mk
+++ b/media/libmedia/Android.mk
@@ -43,7 +43,9 @@
     IEffectClient.cpp \
     AudioEffect.cpp \
     Visualizer.cpp \
-    MemoryLeakTrackUtil.cpp
+    MemoryLeakTrackUtil.cpp \
+    SoundPool.cpp \
+    SoundPoolThread.cpp
 
 LOCAL_SHARED_LIBRARIES := \
 	libui libcutils libutils libbinder libsonivox libicuuc libexpat \