Prevents the WindowManager from requesting empty or negative surfaces.

Windows with a negative Y position can end up in createSurfaceLocked()
with mFrame containing a negative height, causing SurfaceFlinger to go
crazy when asked to create the surface. This change simply guards
against such a situation by instead asking for a 1x1 surface and relying
or later layout operations to resize the window to the appropriate size.

Change-Id: I66f2058f4cd1cf069b12d3d23e6fd340dc76b74e