* build: use python3 to download external binaries (#21184)

* build: use python3 to download external binaries

* Update config.py

(cherry picked from commit d34ba76e)

* update for python3

* Update all the print

* Revert "build: use python3 to download external binaries (#21184)"

This reverts commit 0f4ebda10fcec668afd7a9bcd2fbba800a31e582.

* Revert "Update all the print"

This reverts commit 64a423bdbeeab9751b06d636d5da91be8843f9a2.

* Revert "update for python3"

This reverts commit 349ccafa435832cf22fe7ef11b9144ac6d12d1f0.

* Use older depot_tools for 6-1-x