ziparchive: Use getpagesize() instead of a hardcoded value

Android V will support page size agnostic targets. For
ziparchive, getpagesize() will be used instead of the
hardcoded value for page size.

Bug: 281600291
Test: source build/envsetup.sh
      lunch aosp_cf_arm64_phone_pgagnostic
      m
Change-Id: Ib00afdb30fa363219a9184cfd9a6eff53d15f78b
1 file changed