KAFKA-9760: Add KIP-447 protocol change to upgrade notes (#8350)
KAFKA-9760: Add KIP-447 protocol change to upgrade notes (#8350)

Reviewers: Matthias J. Sax <e388d34fd3c0456122779e95f262c0d70198a168@confluent.io>, Guozhang Wang <guozhang@confluent.io>
guozhangwang/kafka,lindong28/kafka,Chasego/kafka,guozhangwang/kafka,sslavic/kafka,lindong28/kafka,apache/kafka,sslavic/kafka,guozhangwang/kafka,TiVo/kafka,TiVo/kafka,guozhangwang/kafka,Chasego/kafka,Chasego/kafka,lindong28/kafka,TiVo/kafka,sslavic/kafka,TiVo/kafka,sslavic/kafka,apache/kafka,apache/kafka,Chasego/kafka,apache/kafka,lindong28/kafka