Settings: Fix TouchInterceptor widget on tablets

Fix the x position of the dragging view to align to the item to be dragged. Actually, dragging view
is aligned to CENTER and is shown in the middle of the screen in tablets (or devices with tablets
fragments layouts)

Change-Id: I7a061df5a3d297c567103447555c6ecf4f3d836f
Signed-off-by: Jorge Ruesga <jorge@ruesga.com>