Use opaque layout PJRT_Layouts_MemoryLayout in PjRtCApiBuffer::layout() to keep all the layout information.
Use opaque layout PJRT_Layouts_MemoryLayout in PjRtCApiBuffer::layout() to keep all the layout information.

PjRtCApiBuffer::layout() was using PJRT_Buffer_GetMemoryLayout, which will be deprecated. PJRT_Buffer_GetMemoryLayout uses explicit PJRT_Buffer_MemoryLayout which does not contain all the layout information.
