Fix allocation tracking race

Need to instrument the stubs before calling
Heap::SetAlloctrackingEnabled or else we can get this DCHECK failing
DCHECK(!IsAllocTrackingEnabled())

Bug: 27506909

(cherry picked from commit 16e51beb9a771ffe7be833173e3dd5f2dac63892)

Change-Id: I45d6f716ed55371d41e7b7673209166401dbc62e
1 file changed