libril: Export headers

Change-Id: Ie61d8eb47f19fd825713357a538754f05b89d11a
diff --git a/ril/libril/Android.mk b/ril/libril/Android.mk
index 3e59bb5..4330178 100644
--- a/ril/libril/Android.mk
+++ b/ril/libril/Android.mk
@@ -38,6 +38,8 @@
 
 LOCAL_C_INCLUDES += $(LOCAL_PATH)/include
 LOCAL_C_INCLUDES += external/nanopb-c
+LOCAL_C_INCLUDES += $(LOCAL_PATH)/../include
+LOCAL_EXPORT_C_INCLUDE_DIRS := $(LOCAL_PATH)/../include
 
 LOCAL_MODULE:= libril