image_chromeos: Leverage chromite for path translation

chromite's path_util does all of this better and is more resilient to
SDK updates. Let's use it.

While it's ugly, the path is pulled dynamically from 'chromeos_root',
because this might be run standalone, and not part of a CrOS manifest
layout.

BUG=b:275442353
TEST=run it

Change-Id: Ia3a06fa5c1b3049b827e1bce33da0daadbbdd734
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/third_party/toolchain-utils/+/4397062
Commit-Queue: Brian Norris <briannorris@chromium.org>
Reviewed-by: Jordan Abrahams-Whitehead <ajordanr@google.com>
Tested-by: Brian Norris <briannorris@chromium.org>
Reviewed-by: Manoj Gupta <manojgupta@chromium.org>
1 file changed