f an aggregation pipeline targets a viewless timeseries collection, we currently rewrite the pipeline to inject the $_internalUnpackBucket stage. This stage is in charge of translating raw timeseries buckets document into logical timeseries documents.

The problem is that currently we are injecting this stage also for pipelines that do not return raw timeseries buckets document. Instead, we should do it only for pipelines that return raw timeseries buckets documents.

For instance, we should not inject the $_internalUnpackBucket for pipelines that starts with $listCatalog stage.