Remove gMallocLeakZygoteChild.

Bug: 130028357

Test: Verified that call is made and that memory is properly marked in a
Test: child as not in the Zygote.
Change-Id: I9b94637cc0e48eec3bbccfdc1afd531a1ee10a89
Merged-In: I9b94637cc0e48eec3bbccfdc1afd531a1ee10a89
(cherry picked from commit ed364d6c)