packaging: setup: aio: fix ssh issues

1. If ~root/.ssh is missing and selinux enabled, it will be created
   without proper selinux attributes, causing ssh to fail.

2. If ~root/.ssh is missing it is created using mode 0755 and not 0700.

3. Validate /etc/ssh/sshd_config, if PermitRootLogin is no then fail
   early.

Buf-Url: https://bugzilla.redhat.com/show_bug.cgi?id=1036209
Change-Id: Icfe55ccf4535792fed69912553d86a53dec3764b
Signed-off-by: Alon Bar-Lev <alonbl@redhat.com>