Add support for custom buffer sizes.

Add native window properties NATIVE_WINDOW_SET_BUFFERS_SIZE to the
perform function of SurfaceTextureClient to set the user defined size
of graphic buffers.

Change-Id: I1dc2203990a3641fbb9ddab9a86f7e9017f05270
libgui: Add support to update buffer geometry.

Add native window properties NATIVE_WINDOW_UPDATE_BUFFERS_GEOMETRY
to the perform function of SurfaceTextureClient and SurfaceTexture
to update the width, height and format of the buffer dynamically
from the client before queue buffer call.

Change-Id: I62447fcf523b507d534085cd0835f55a978c4ead