Fix the re-roll metric

The re-roll metric made the assumption that the ingestion and rollup contexts are always running on the same JVM and ingestion context is pulling the state for all the shards.
We can fix this by emitting the metric at 2 places:

1. On the ingestion context, emit the metric if we are rolling up for that shard as well
2. Always emit a metric for updates coming from shardstatepuller on read.