Robustly fixed issue where migration from different versions of DB data

tables was causing crashes upon grid size switching.

Bug: 304687723
Test: Verified behavior through unit test. Also manually tested that
factory resetting device -> adding shortcuts to the workspace ->
changing the grid size didn't cause any issues and resulted in normal
behavior.

Change-Id: I1945004d2c9a2d6f2b74d9597b39763ed4962e7b