Convert libchrome scripts to python 3 am: 22b8126fb5 am: 2f8caa9aa8 am: ac5ab8de4e am: 182e9f2b7a

Original change: https://android-review.googlesource.com/c/platform/external/libchrome/+/2210336

Change-Id: I36966bc09ee84d43346f82284b6e2420f4a76cc3
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>