Preload public native libraries when starting a zygote
This lets other users of libnativeloader (like dex2oat)
avoid unnecessary cold loads of libandroid.so which could
take up to a second.
Bug: http://b/27245894
(cherry picked from commit b0824979be2653ba300382b52c1b1236fd44f0de)
Change-Id: I04a640c104dba5b585a59d63270e81b6c9ad6f7e