[ubuntu] Rename build scripts (#8866)

* [ubuntu] Rename build scripts

* [ubuntu] Change reboot to inline shell

* [ubuntu] Move disk space validation to pester tests

* [ubuntu] Rename helper and tests files

* [ubuntu] Changes to cleanup, post-deployment and r scripts

images/ubuntu/scripts/build/configure-dpkg.sh

@@ -0,0 +1,29 @@
+#!/bin/bash -e
+################################################################################
+##  File:  configure-dpkg.sh
+##  Desc:  Configure dpkg
+################################################################################
+
+# This is the anti-frontend. It never interacts with you  at  all,
+# and  makes  the  default  answers  be used for all questions. It
+# might mail error messages to root, but that's it;  otherwise  it
+# is  completely  silent  and  unobtrusive, a perfect frontend for
+# automatic installs. If you are using this front-end, and require
+# non-default  answers  to questions, you will need to preseed the
+# debconf database
+echo 'DEBIAN_FRONTEND=noninteractive' | tee -a /etc/environment
+
+# dpkg can be instructed not to ask for confirmation
+# when replacing a configuration file (with the --force-confdef --force-confold options)
+cat <<EOF >> /etc/apt/apt.conf.d/10dpkg-options
+Dpkg::Options {
+  "--force-confdef";
+  "--force-confold";
+}
+EOF
+
+# hide information about packages that are no longer required
+cat <<EOF >> /etc/apt/apt.conf.d/10apt-autoremove
+APT::Get::AutomaticRemove "0";
+APT::Get::HideAutoRemove "1";
+EOF