HDFS-7257. Add the time of last HA state transition to NN's /jmx page. Contributed by Charles Lamb.
HADOOP-11170. ZKDelegationTokenSecretManager fails to renewToken created by a peer. (Arun Suresh and Gregory Chanan via kasha)

(cherry picked from commit db45f047ab6b19d8a3e7752bb2cde10827cd8dad)
HDFS-7223. Tracing span description of IPC client is too long (iwasakims via cmccabe)
(cherry picked from commit 5b56ac4c72d69d1b3d6feec9d96c9d62eb02d28c)