ART: Do not free allocation listener in heap destructor

Do not deallocate on exit. Libraries are freed only after the heap
has already been destroyed.

Bug: 31684277
Bug: 31684920
Test: m test-art-host
Change-Id: I7061c4500a9ad314e2c00d7d722bb3372dff4810
diff --git a/runtime/gc/heap.cc b/runtime/gc/heap.cc
index 45bd87b..f4a3aea 100644
--- a/runtime/gc/heap.cc
+++ b/runtime/gc/heap.cc
@@ -1246,9 +1246,6 @@
         << " total=" << seen_backtrace_count_.LoadRelaxed() +
             unique_backtrace_count_.LoadRelaxed();
   }
-  // Delete any still registered allocation listener.
-  AllocationListener* l = GetAndOverwriteAllocationListener(&alloc_listener_, nullptr);
-  delete l;
 
   VLOG(heap) << "Finished ~Heap()";
 }