toolchain_utils: replace gsutil with gsutil.py

Remove dependency on pre-installed gLinux software.
gsutil.py comes from depot_tools which is part of chrotomation setup.

BUG=None
TEST=tested locally on chrotomation.mtv

Change-Id: I8fcef35a3c229ec06639a56b02c5751b4cedfc95
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/third_party/toolchain-utils/+/2460835
Reviewed-by: George Burgess <gbiv@chromium.org>
Reviewed-by: Manoj Gupta <manojgupta@chromium.org>
Tested-by: George Burgess <gbiv@chromium.org>
1 file changed