Bug: enable zookeeper log purge

[stevendborrelli]

Zookeeper logs and snapshots are not currently being purged from the system. This needs to be enabled as part of cleanup to keep root disks from filling on busy clusters.

autopurge.snapRetainCount
(No Java system property)

New in 3.4.0: When enabled, ZooKeeper auto purge feature retains the autopurge.snapRetainCount most recent snapshots and the corresponding transaction logs in the dataDir and dataLogDir respectively and deletes the rest. Defaults to 3. Minimum value is 3.

autopurge.purgeInterval
(No Java system property)

New in 3.4.0: The time interval in hours for which the purge task has to be triggered. Set to a positive integer (1 and above) to enable the auto purging. Defaults to 0.

[stevendborrelli]

Fixed via #1309