Enable rosalloc by default.

Bug: 9986565
Change-Id: I485341d30a21704ddbc45d8f531ef5593a358bb5
diff --git a/runtime/gc/heap.h b/runtime/gc/heap.h
index 6e8890c..3da3943 100644
--- a/runtime/gc/heap.h
+++ b/runtime/gc/heap.h
@@ -109,7 +109,7 @@
 static constexpr HeapVerificationMode kDesiredHeapVerification = kNoHeapVerification;
 
 // If true, use rosalloc/RosAllocSpace instead of dlmalloc/DlMallocSpace
-static constexpr bool kUseRosAlloc = false;
+static constexpr bool kUseRosAlloc = true;
 
 class Heap {
  public: