The date and time when the boot image memory was last
successfully synced from the current Active unit to the
Standby unit(s).
This object will remain uninstantiated if no sync has yet
taken place since the current Active CPU was initialized
or if a Standby unit was forced to take over before the
initial database sync was completed.
Since automatic boot image memory syncs are event driven
and may be disabled by configuration, this time doesn't
directly reflect whether Standby boot image memory is
in sync with the Active unit.
Instead, see the cRfSupSysBootImageOper object to determine
whether Standby boot image memory is in sync with the Active
unit.