Disable Python 2 variant, but keep sources filegroup. am: 665a6ab3f7 am: 4cd48834ec

Original change: https://android-review.googlesource.com/c/platform/external/python/httplib2/+/2221133

Change-Id: Ib0c83fab3b284265f4a48a229442e87dcd5f1413
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>