logrotate doesn't change the permissions of the existing log files

Issue

• Customer complained that the permissions of the existing /var/log/btmp* files didn't change after /etc/logrotate.d/btmp was changed from "create 0660 root utmp" to "create 0600 root utmp" and logrotate command was executed.

# sudo  sh -c "ls -lt /var/log/btmp*" | cat -n
    1  -rw-rw---- 1 root utmp 12288 Mar 18 09:18 /var/log/btmp
    2  -rw-rw---- 1 root utmp   119 Feb 18 19:02 /var/log/btmp-20220301.gz
    3  -rw-rw---- 1 root utmp    20 Jan 12 20:39 /var/log/btmp-20220201.gz