OCPBUGS-33945: select required SSHD timeout rule

The rule sshd_set_idle_timeout used to require rule sshd_set_keepalive_0
for Red Hat linuxes. But after #11815 it started to require rules
sshd_set_keepalive.

This selects the rule that satifyes the requirement.

controls/nist_rhcos4.yml

@@ -260,7 +260,7 @@ controls:
  rules:
  - sshd_set_idle_timeout
  - var_sshd_set_keepalive=0
- - sshd_set_keepalive_0
+ - sshd_set_keepalive
  description: |-
  The organization requires that users log out when [Assignment: organization-defined time-period of expected inactivity or description of when to log out].