Fix build issue

Test: make

Change-Id: I5563ff049ddc384556976f577a6d0ebc020516c8
Signed-off-by: François Gaffie <francois.gaffie@renault.com>
diff --git a/services/audiopolicy/tests/Android.mk b/services/audiopolicy/tests/Android.mk
index 513312e..2ccb542 100644
--- a/services/audiopolicy/tests/Android.mk
+++ b/services/audiopolicy/tests/Android.mk
@@ -41,6 +41,9 @@
   libmedia_helper \
   libutils
 
+LOCAL_HEADER_LIBRARIES := \
+  libmedia_headers
+
 LOCAL_SRC_FILES := \
   systemaudio_tests.cpp \