papi: vpp_serializer.py - replace slow bytes() with fast bytearray()
papi: vpp_serializer.py - replace slow bytes() with fast bytearray()

https://docs.python.org/3/library/stdtypes.html

"if concatenating bytes objects, you can similarly use bytes.join() or io.BytesIO, or you can do in-place concatenation with a bytearray object. bytearray objects are mutable and have an efficient overallocation mechanism"

Type: improvement

Signed-off-by: Viktor Velichkin <9d41b675afa0ad3318e3fdafc6b3aae332923774@yandex.ru>
Change-Id: Id20d337f909cce83fcd9e08e8049bb0bf5970fbc

FDio/vpp,FDio/vpp,FDio/vpp,chrisy/vpp,FDio/vpp,chrisy/vpp,FDio/vpp,chrisy/vpp,chrisy/vpp,chrisy/vpp,FDio/vpp,chrisy/vpp,FDio/vpp,chrisy/vpp,FDio/vpp,chrisy/vpp