Disable unused Python 2 variant. am: 4b316bcda8 am: f87562050e

Original change: https://android-review.googlesource.com/c/platform/external/python/enum34/+/2221450

Change-Id: Ic17d7561818bd532277b6ebdb3ddb0d811eb7802
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>