rhel: make sure previous-hostname file ends with a new line (#2108)
BZ: 2184608
Cherry-picked the following commit from cloud-init upstream without any conflicts:
rhel: make sure previous-hostname file ends with a new line (#2108)
cloud-init strips new line from "/etc/hostname" on rhel distro when processing
"/var/lib/cloud/data/previous-hostname". Although this does not pose a serious
issue, it is still better if the behavior is similar to other distros like
Ubuntu where /previous-hostname does end with a new line. Fix this issue by
using hostname parser in rhel similar to debian.
Signed-off-by: Ani Sinha <anisinha@redhat.com>
(cherry picked from commit 6d42aa8e2c1a5454a658ab4e2b9cead2677c77cd)