Merge the 2018-05-05 SPL branch from AOSP-Partner into staging/n/fp2

* origin/security-aosp-nyc-mr2-release:
  String16: remove integer overflows
  libnetutil: Check dhcp respose packet length
  zip_archive: reject files that don't start with an LFH signature.
  Fix integer overflow in utf{16,32}_to_utf8_length
  Fix out of bound read in libziparchive

Issue: FP2N-106
Change-Id: I71933c515a0f958e02ed1e4af26b999a27665d12