Do not delete chost widgets when opening DB.

During restore, the data can be in inconsistant state, as the
system is yet to give us the widget map. Deleting the widget during
open would cause the AppWidgetRestoredReceiver to store the widget id
after it has been deleted.

Bug: 37935101
Bug: 38029633
Change-Id: Id3b8766229718239ae784794e848dcfbc74658ac