community/cloud-init: Fix wakeonlan and add post-install message

Fix wakeonlan support in Network Config v2 YAML file.

Add post-install script that displays message about running
setup-cloud-init to finish configuration.
7 jobs for !14045 with add-wakeonlan-patch in 1 minute and 39 seconds
detached
Status Job ID Name Coverage
  Lint
passed #235884
x86_64 docker-alpine
lint

00:00:26

 
  Build
passed #235889
aarch64 ci-build docker-alpine
build-aarch64

00:00:50

passed #235890
armv7 ci-build docker-alpine
build-armv7

00:01:03

passed #235888
ppc64le ci-build docker-alpine
build-ppc64le

00:01:12

passed #235887
s390x ci-build docker-alpine
build-s390x

00:00:40

passed #235886
x86 ci-build docker-alpine
build-x86

00:00:43

passed #235885
x86_64 ci-build docker-alpine
build-x86_64

00:00:38