Step down icon size when isVerticalBarLayout for responsive grids

Fix the icon step down logic to resize the icons to fit when isVerticalBarLayout and the iconSize does not fit inside the cellHeight.

Bug: 316087877
Bug: 314285621
Flag: ACONFIG com.android.launcher3.enable_responsive_workspace TEAMFOOD
Test: DeviceProfileDumpTest
Test: DeviceProfileAlternativeDisplaysDumpTest
Change-Id: I3a1fd28b729435eaf2dbbff650e4d13d33d77ff8