Revert "Add support for generated previews to People Space widget"

This reverts commit b3a44252.

Reason for revert: Droid-monitored triggered revert for breakages in b/329679427. Will be running through ABTD for verification and before submitting the revert.

Change-Id: If24e0a5a9d025b8bdd492a9562fabb8b892d7314