libmediaplayerservice: fix warnings, make warnings errors, use clang

Change-Id: I1b2f6b65c5abbc366068a60b8909104f31b94228
diff --git a/media/libmediaplayerservice/nuplayer/Android.mk b/media/libmediaplayerservice/nuplayer/Android.mk
index fca08e2..20193c3 100644
--- a/media/libmediaplayerservice/nuplayer/Android.mk
+++ b/media/libmediaplayerservice/nuplayer/Android.mk
@@ -25,6 +25,9 @@
 	$(TOP)/frameworks/av/media/libmediaplayerservice              \
 	$(TOP)/frameworks/native/include/media/openmax
 
+LOCAL_CFLAGS += -Werror -Wall
+LOCAL_CLANG := true
+
 LOCAL_MODULE:= libstagefright_nuplayer
 
 LOCAL_MODULE_TAGS := eng