[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-apt.sh

@@ -0,0 +1,47 @@
+#!/bin/bash -e
+################################################################################
+##  File:  configure-apt.sh
+##  Desc:  Configure apt, install jq and apt-fast packages.
+################################################################################
+
+# Stop and disable apt-daily upgrade services;
+systemctl stop apt-daily.timer
+systemctl disable apt-daily.timer
+systemctl disable apt-daily.service
+systemctl stop apt-daily-upgrade.timer
+systemctl disable apt-daily-upgrade.timer
+systemctl disable apt-daily-upgrade.service
+
+# Enable retry logic for apt up to 10 times
+echo "APT::Acquire::Retries \"10\";" > /etc/apt/apt.conf.d/80-retries
+
+# Configure apt to always assume Y
+echo "APT::Get::Assume-Yes \"true\";" > /etc/apt/apt.conf.d/90assumeyes
+
+# APT understands a field called Phased-Update-Percentage which can be used to control the rollout of a new version. It is an integer between 0 and 100.
+# In case you have multiple systems that you want to receive the same set of updates, 
+# you can set APT::Machine-ID to a UUID such that they all phase the same, 
+# or set APT::Get::Never-Include-Phased-Updates or APT::Get::Always-Include-Phased-Updates to true such that APT will never/always consider phased updates.
+# apt-cache policy pkgname
+echo 'APT::Get::Always-Include-Phased-Updates "true";' > /etc/apt/apt.conf.d/99-phased-updates
+
+# Fix bad proxy and http headers settings
+cat <<EOF >> /etc/apt/apt.conf.d/99bad_proxy
+Acquire::http::Pipeline-Depth 0;
+Acquire::http::No-Cache true;
+Acquire::BrokenProxy    true;
+EOF
+
+# Uninstall unattended-upgrades
+apt-get purge unattended-upgrades
+
+echo 'APT sources'
+cat /etc/apt/sources.list
+
+apt-get update
+# Install jq
+apt-get install jq
+
+# Install apt-fast using quick-install.sh
+# https://github.com/ilikenwf/apt-fast
+bash -c "$(curl -fsSL https://raw.githubusercontent.com/ilikenwf/apt-fast/master/quick-install.sh)"