Codec2Buffer: add size info to client-based output byte buffer

In byte-buffer mode of Codec2.0 ConstGraphicBlockBuffer would be allocated
bigger size (width * height * 4). Adding size info as image convertor
reported by setRange() is beneficial for app to be able to get actual
frame buffer size in byte-buffer mode.

Bug: 130398258
Bug: 132140935
Test: manual
Test: run CtsMediaTestCases
Change-Id: Ieb04d77ac28e88d687fa79fbd8dad2584e83a63b