App row padding is now consistent for all grid sizes. Also fix when 2x2 allApp icons get super big.

Added consistent padding to each app row.

Bug: 229789736
Bug: 229791507
Bug: 228320417
Bug: 230870213
Test: Manual on Raven

Change-Id: Ice1c8be361f009994a8e0960a30da04fc1c0c218
3 files changed