MINOR: Fix Partition::toString method (#6971)
MINOR: Fix Partition::toString method (#6971)

The AllReplicas was only printing remote replica ids. This change prints
all ids, including local one.

Reviewers: José Armando García Sancio <a8f36d709c55b131453e2fdebab89d11b4e5c5e0@users.noreply.github.com>, Jason Gustafson <jason@confluent.io>
sslavic/kafka,TiVo/kafka,sslavic/kafka,guozhangwang/kafka,apache/kafka,noslowerdna/kafka,lindong28/kafka,lindong28/kafka,noslowerdna/kafka,TiVo/kafka,Chasego/kafka,apache/kafka,TiVo/kafka,lindong28/kafka,noslowerdna/kafka,sslavic/kafka,guozhangwang/kafka,sslavic/kafka,apache/kafka,guozhangwang/kafka,Chasego/kafka,noslowerdna/kafka,Chasego/kafka,lindong28/kafka,TiVo/kafka,Chasego/kafka,guozhangwang/kafka,apache/kafka