aapt: set interlace handling for png_read_update_info

Summary:
When png_read_update_info is called, interlace handling
should already be set. This is the recommended usage even
on > libpng 1.5.1 which takes into account if the image is
interlaced.

Test Plan: verified

Reviewers: randall.rushing, synergy

Reviewed By: synergy

Differential Revision: http://review.codefirex.com/D452