ANativeWindow: add setters for dimensions and fmt

This change adds two new 'perform' setters to set the dimensions and
pixel format of the buffers that will be dequeued from the
ANativeWindow.  These new setters provide the same functionality as
_SET_BUFFERS_GEOMETRY, but allow the format and dimensions to be set
independently.  The _SET_BUFFERS_GEOMETRY setter is still supported to
maintain backwards compatibility.

Change-Id: Ib49b7798ffebe61eff2c8e4202fc3048cfec7bdd