Configure ImageMagick when running a non-installed Linux binary.
Configure ImageMagick when running a non-installed Linux binary.

Added configuration of ImageMagick via environment variables
See http://www.imagemagick.org/script/resources.php

Tested:
Verified it's possible to build Zooshi assets on Linux with
ImageMagick running from the prebuilts directory.

Bug: 23314076
Change-Id: I0f53f36b6fc3bee54a7e48f72675a9508a82414f

google/zooshi,google/zooshi,google/zooshi,google/zooshi,google/zooshi