Updated LauncherIcon to only show secondary drop target

Introduce LauncherIcon support of only displaying only secondary drop
target for the scenario when expanded view is show in shell and the
bubble bar can not be shown from shell.
It is not possible to show both views in the shell since the taskbar
window is on top of the shell window (layering issue).

Bug: 411505605
Test: DropTargetManagerTest
Test: DragZoneFactoryTest
Flag: com.android.wm.shell.enable_create_any_bubble
Change-Id: Id04f71730af9f50af9c61790357e3bfed4f870a4