Fix handling of wrapped processes [part 2]

Drop privileges only if we're root. Zygote.preloadClasses can
be called from a non-root uid / gid in the case of wrapped classes,
so we shouldn't die from the resulting EPERM.

Change-Id: Ie3fbe50a17ec49bcbcb875c3a2ee1e1a3a62e88d
1 file changed