Disable integer overflow sanitizer in grep.

Disables integer overflow sanitization in grep on integer sanitized
builds.

Bug: 30969751
Test: Compiles.
Change-Id: I2668ef6f2261a86f17d2a0f04d5ec7a3c0336ff1

toolbox/Android.bp

@@ -40,6 +40,10 @@ cc_defaults {
     cflags: common_cflags,
     local_include_dirs: ["upstream-netbsd/include/"],
     symlinks: ["egrep", "fgrep"],
+
+    sanitize: {
+        integer_overflow: false,
+    },
 }
 
 cc_binary {