private PartitionedRegion getPersistentLeader() {
    PartitionedRegion leader = ColocationHelper.getLeaderRegion(partitionedRegion);
    return findPersistentRegionRecursively(leader);
  }
Check to see if any colocated region of the current region is persistent. It's not enough to
check just the leader region, because a child region might be a persistent parallel WAN queue,
which is allowed.

@return the most senior region in the colocation chain (closest to the leader) that is
        persistent.
geode-core/src/main/java/org/apache/geode/internal/cache/PRHARedundancyProvider.java