Making sure that we drag icon far enough to cross the threshold

Tests dragged icon from all apps to workspace by dragging it to the
center of the screen.

If the icon is close enough to the center, this may not trigger the
dragging condition.

Fixing by dragging far enough.

Bug: 133009122
Change-Id: I68127714ab3694f2639b4acf530e2736ca4dbdf3