libutils: integer sanitization

For sanity.

Fixes: 160342252
Test: manually introduce overflow for "ubsan: mul-overflow"
Change-Id: I292039eaef24582f05dd9f0fef011f0ece8364ed
diff --git a/libutils/Android.bp b/libutils/Android.bp
index 7392806..9bd15c6 100644
--- a/libutils/Android.bp
+++ b/libutils/Android.bp
@@ -78,6 +78,9 @@
         "libcutils",
         "liblog",
     ],
+    sanitize: {
+        misc_undefined: ["integer"],
+    },
 
     target: {
         android: {