fix the issue widget id wasn't being migrated in backup

After SuW the favorite table is copied into backup table, but the widget
id in the backup table hasn't been migrated. This introduces general
unstabality and can sometimes leads to the disappearance of widgets
after a restore.

Bug: 171774227
Test: run Backup Restore flows and verified database status with arbitrary
logging

Change-Id: If275a6b5395504d6de90e26c3998f759e797f6e1