When the bubble bar is stashed and an icon is dragged from the search
grid towards it, the bubble bar should be un-stashed. Conversely, if the
icon is dragged to the opposite location of the stashed bubble bar, the
handle should teleport out, and the collapsed bubble bar should
teleport in.
This change implements logic that addresses this behavior.
Bug: 399678274
Test: Manual. Drag and drop application icons from the search grid to
the bubble bar drop areas.
Flag: com.android.wm.shell.enable_create_any_bubble
Change-Id: Ief9ef3e5c24f8199b2812fd0adf63ae3f6cf8f32