[12/n] Letterbox Education: relayout but don't update surface position when bounds change.

The position of the letterbox education is fixed to the top left corner (0,0) of the task (parent surface) so there is no need to set the position of the surface because this is the default position of a surface (relative to its parent).

We do however need to update the dimensions of the layout (relayout) when the task bounds change because they are dependant on them.

Finally, there is no need to relayout when View#onLayout is called because neither the surface position nor the layout's dimensions depend on changes in the layout itself.

Bug: 215314668
Test: N/A
Change-Id: I17850b4106b13809e51cf2b9b83c6d67151a9df5