pigz usually has a zopfli version bundled. But since we denested zopfli,
the include path needs to be adjusted slightly.

Bug: 243389125
Bug: 315488400
Change-Id: Ia90ada0778a5b6b78991d5601753a9fa513491ef
Signed-off-by: Matthias Maennich <maennich@google.com>