Translate IconMenu to top / left of thumbnail view

When splitting a task that is already part of a split app pair from the
 TaskBar, with the enableOverviewIconMenu feature enabled, position the
 IconMenu to the left of a leftRightSplitApp pair, or the top of a
 topBottomSplitApp pair

Fixes: 317001670
Test: Manual
Flag: ACONFIG com.android.launcher3.enable_overview_icon_menu TEAMFOOD
Flag: ACONFIG com.android.launcher3.enable_grid_only_overview TEAMFOOD
Change-Id: I4740d7c96635ee9542f7061938baf6fbf2ca01d4