security/heimdal*: Handle other types of garbage data

In addition to garbage realm data, also handle garbage dbname, acl_file,
stash_file, and invalid bitmask garbage data.

PR: 267912
Reported by: Robert Morris <rtm@lcs.mit.edu>

(cherry picked from commit 8cafd5bc0d866a425eb883e00cef02df1ef31db4)