Enable fsanitize unsigned-integer-overflow in webm

Change-Id: If1024d67fb5fcc1444f4e07f83a9552684252c42
diff --git a/media/libstagefright/webm/Android.mk b/media/libstagefright/webm/Android.mk
index bc53c56..7ce436a 100644
--- a/media/libstagefright/webm/Android.mk
+++ b/media/libstagefright/webm/Android.mk
@@ -5,6 +5,7 @@
 
 LOCAL_CFLAGS += -Werror -Wall
 LOCAL_CLANG := true
+LOCAL_SANITIZE := unsigned-integer-overflow
 
 LOCAL_SRC_FILES:= EbmlUtil.cpp        \
                   WebmElement.cpp     \