Reorganize LatinIME native build directory structure.  Now it got NDK friendly.

Change-Id: I0f62ce8a6a4d2b6134db698f8b8d0576616e524d
diff --git a/Android.mk b/Android.mk
index 8f1acc5..91b2fbb 100644
--- a/Android.mk
+++ b/Android.mk
@@ -12,6 +12,4 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-LOCAL_PATH := $(call my-dir)
-
-include $(call all-makefiles-under,$(LOCAL_PATH))
+include $(call all-subdir-makefiles)