Upgrade six to 1.16.0 am: 7a202e1064

Original change: https://android-review.googlesource.com/c/platform/external/python/six/+/3162722

Change-Id: I4b535e851aed099f2a704d73677a367922ccb5e5
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>