Remove widgets that no longer fit the workspace in their current spans.

This can happen when display size changes.
We compare span sizes of widget in the db to the min sizes of the widget
in the current display size. If the widget can no longer fit in its existing
spans, we remove it.

Bug: 168818961
Change-Id: I6b095d2eeaeda95bfa91baec89cb54660695b60b