Revert "Revert "Finish fixing Zygote descriptor leakage problem""

This reverts commit 2fdc1d1065c69b2577252eb8ebf34e7c08670f52.

Change-Id: I96e671b459f208b190dbf0d0accd2c75c2c8281d
Merge "Revert "Revert "Finish fixing Zygote descriptor leakage problem""" into kitkat