Revert "Save generated previews in AppWidgetService"

This reverts commit 63a8e1678db1e0f07ee06e781b6e8a8d98bbfc28.

Reason for revert: DroidMonitor: Potential culprit for http://b/376268538 - verifying through ABTD before revert submission. This is part of the standard investigation process, and does not mean your CL will be reverted

Change-Id: I3550d28ffa66f8a46d00686af21182c0382631ec
3 files changed