trace_processor: add support for building on Android

Change-Id: I4ef68658819c84919011f56221cb4fd36d532566
diff --git a/buildtools/BUILD.gn b/buildtools/BUILD.gn
index db99b19..3fa3d2f 100644
--- a/buildtools/BUILD.gn
+++ b/buildtools/BUILD.gn
@@ -852,6 +852,7 @@
   ]
   configs -= [ "//gn/standalone:extra_warnings" ]
   public_configs = [ ":linenoise_config" ]
+  cflags = [ "-Wno-tautological-unsigned-zero-compare" ]
 }
 
 if (use_libfuzzer) {