Really plumb chroot_lib 'out_path'

Any time we construct a chroot with a non-default path, we want to
provide 'out_path' too. We may make this fatal in the future.

BUG=b:265885353
TEST=./run_tests

Change-Id: Iaae32a6b10acde6cebf1f0f8feba8585dd0f8333
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/chromite/+/4328428
Tested-by: Brian Norris <briannorris@chromium.org>
Reviewed-by: Jack Rosenthal <jrosenth@chromium.org>
Commit-Queue: Brian Norris <briannorris@chromium.org>
diff --git a/api/controller/image_unittest.py b/api/controller/image_unittest.py
index efe3bff..8b2c93b 100644
--- a/api/controller/image_unittest.py
+++ b/api/controller/image_unittest.py
@@ -249,7 +249,9 @@
                 image_service, func.__name__
             )
         self.chroot = chroot_lib.Chroot(
-            path=self.tempdir, chrome_root=self.tempdir
+            path=self.tempdir / "chroot",
+            chrome_root=self.tempdir,
+            out_path=self.tempdir / "out",
         )
         board = "chell"
         sysroot_path = "/build/%s" % board