The NDK doesn't have libutils.

Change-Id: I61f4e0917954d1557fe4cd1605aecaded68d4a97
diff --git a/src/modules/audio_coding/codecs/isac/fix/source/Android.mk b/src/modules/audio_coding/codecs/isac/fix/source/Android.mk
index b9931c4..2794a9c 100644
--- a/src/modules/audio_coding/codecs/isac/fix/source/Android.mk
+++ b/src/modules/audio_coding/codecs/isac/fix/source/Android.mk
@@ -176,6 +176,7 @@
 LOCAL_NDK_STL_VARIANT := $(WEBRTC_STL)
 LOCAL_SDK_VERSION := 14
 LOCAL_MODULE := $(LOCAL_MODULE)_$(WEBRTC_STL)
+LOCAL_SHARED_LIBRARIES :=
 endif
 include $(BUILD_NATIVE_TEST)
 endif