Update extra space allocations for taller devices.

- Take less space from cells
- Distribute some of the empty space above the workspace
- Already confirmed from previous testing that these thresholds
  only affect taller devices

Bug: 194688362
Test: long press on app icons,
      test drag and drop bounds
      test drop target bounds
      test folder opening bounds
      test all grids on taller devices

Change-Id: If90b7663ab4afedca1193bdd73a0ae38a1f25243