Revert "pam: upgraded package to upstream"

This reverts commit b2f3e6714b405cec58fdd760d3bb1f52d114634a.

Reason for revert: Validation tests cannot SSH to VMs

Change-Id: I1b7af34c9983d931eaae28473044ffbb82835f50
Reviewed-on: https://cos-review.googlesource.com/c/third_party/overlays/portage-stable/+/8640
Reviewed-by: Roy Yang <royyang@google.com>
Tested-by: Cusky Presubmit Bot <presubmit@cos-infra-prod.iam.gserviceaccount.com>
7 files changed