Fix writeByteArray/writeInt32Array size on x64

writeByteArray writes the size using sizeof(size_t), however it is always
read using readInt32(). On devices where sizeof(size_t) != 4 this causes
extra bytes to be written.

BUG: 22204736
Change-Id: I8d4507b6b616857ef5827f1fe9da0907d09abf0e