libion: move ion.h into local include directory

Export it to users of libion with LOCAL_C_EXPORT_INCLUDE_DIRS

Change-Id: I4d00a9dd2e99953723994d0304ca77e0ad50a3a9
diff --git a/libion/Android.mk b/libion/Android.mk
index 5121fee..ae99ac5 100644
--- a/libion/Android.mk
+++ b/libion/Android.mk
@@ -5,11 +5,14 @@
 LOCAL_MODULE := libion
 LOCAL_MODULE_TAGS := optional
 LOCAL_SHARED_LIBRARIES := liblog
+LOCAL_C_INCLUDES := $(LOCAL_PATH)/include
+LOCAL_EXPORT_C_INCLUDE_DIRS := $(LOCAL_PATH)/include
 include $(BUILD_SHARED_LIBRARY)
 
 include $(CLEAR_VARS)
 LOCAL_SRC_FILES := ion.c ion_test.c
 LOCAL_MODULE := iontest
 LOCAL_MODULE_TAGS := optional tests
+LOCAL_C_INCLUDES := $(LOCAL_PATH)/include
 LOCAL_SHARED_LIBRARIES := liblog
 include $(BUILD_EXECUTABLE)
diff --git a/include/ion/ion.h b/libion/include/ion/ion.h
similarity index 100%
rename from include/ion/ion.h
rename to libion/include/ion/ion.h