Remove aactl prefix in shortDescription field of vulnerability Occurrence

[taechae]

Currently the shortDescription field of vulnerability occurrences contain a "aactl-" prefix. This should be removed so that the short description contains only the vulnerability ID.

  "noteName": "projects/taechae/notes/aactl-CVE-2011-3374",
    "shortDescription": "aactl-CVE-2011-3374",