ART: Clean up base/utils.h

Remove dead code. Remove unnecessary includes.

Bug: 115837065
Bug: 119869270
Test: m
Change-Id: Ieb07546e9ebd476b7b1459fb8dd6cf5545d0af20
diff --git a/runtime/gc/heap.cc b/runtime/gc/heap.cc
index 86135c1..4a2c8fa 100644
--- a/runtime/gc/heap.cc
+++ b/runtime/gc/heap.cc
@@ -36,6 +36,7 @@
 #include "base/stl_util.h"
 #include "base/systrace.h"
 #include "base/time_utils.h"
+#include "base/utils.h"
 #include "common_throws.h"
 #include "debugger.h"
 #include "dex/dex_file-inl.h"