DCP/2 analysis doesn't populate `file_core.content_description`

[theathorn]

content_description is optional but to allow users to find files by a human-readable, generalized description of a file's content, this property should be set to one or more terms from the

https://www.ebi.ac.uk/ols/ontologies/edam/terms?iri=http%3A%2F%2Fedamontology.org%2Fdata_0006

ontology. For example,

[{"ontology":"data:1383","ontology_label":"Nucleic acid sequence alignment"}]

instead of an empty array

[]

[melainalegaspi]

@hannes-ucsc to specify details for description.

[hannes-ucsc]

Description specified.