Removed log spam from the Zygote.

This patch removes several debugging log messages.  These messages were
useful when the `FDs to ignore` list was usually empty, but with the
addition of USAPs this has become spammy.

(cherry picked from commit da0a9cd0)

Test: Build
Bug: 130172109
Change-Id: Id166990a63f20efb3bf6ffd5b697efd436d50921
Merged-In: Id166990a63f20efb3bf6ffd5b697efd436d50921