GetEstimatedRangeSizeBytes can cause PacketLimitExceeded error on commit proxies

[jzhou77]

As reported here, if GetEstimatedRangeSizeBytes API uses a large key range, it can cause PacketLimitExceeded errors on commit proxies. This is because getStorageMetricsLargeKeyRange() invokes getKeyRangeLocations() to obtain location information for all shards within the specified key range. For a large range, the size of location information is unbounded and may exceed the packet size limit.