Switch to the seekable mode for unpacking zip archives.
Switch to the seekable mode for unpacking zip archives.

Before, we were using streamable mode which was very slow. This patch forces
libarchie to use a seekable mode, which is way much faster.

TEST=Tested manually that it's way much faster.
BUG=432759

Change-Id: Ie8aa36da7cf2886ff058e8521aadbe1b965c60b8

vapier/chrome-ext-wicked-good-unarchiver,vapier/chrome-ext-wicked-good-unarchiver,vapier/chrome-ext-wicked-good-unarchiver,vapier/chrome-ext-wicked-good-unarchiver,vapier/chrome-ext-wicked-good-unarchiver