[Packaging] Add Ubuntu 21.04 Hirsute Hippo support

[jiasli]

Description

Fix #19313, #18703, #18493, #19235, #18714, #18420, #18356, #17713, #16875, #18542

Old Azure CLI hirsute from Ubuntu universe repo is installed

If a user manually add Azure CLI software repository from Microsoft Linux repo following https://docs.microsoft.com/en-us/cli/azure/install-azure-cli-linux?pivots=apt#option-2-step-by-step-installation-instructions, /etc/apt/sources.list.d/azure-cli.list will contain

deb [arch=amd64] https://packages.microsoft.com/repos/azure-cli/ hirsute main

As https://packages.microsoft.com/repos/azure-cli/dists/ doesn't have hirsure, apt update will fail

E: The repository 'https://packages.microsoft.com/repos/azure-cli hirsute Release' does not have a Release file.
N: Updating from such a repository can't be done securely, and is therefore disabled by default.

Then when apt install azure-cli is run, Azure CLI from Ubuntu universe repo (https://packages.ubuntu.com/hirsute/azure-cli) will be installed.

⚠ The Azure CLI from Ubuntu universe repo is not maintained by Microsoft.

# apt show azure-cli
Package: azure-cli
Version: 2.18.0-1
Priority: optional
Section: universe/python
Origin: Ubuntu
Maintainer: Ubuntu Developers <ubuntu-devel-discuss@lists.ubuntu.com>
Original-Maintainer: Debian Python Team <team+python@tracker.debian.org>
Bugs: https://bugs.launchpad.net/ubuntu/+filebug
Installed-Size: 15.4 kB
Depends: python3:any, python3-azure-cli (>= 2.18.0-1)
Homepage: https://github.com/Azure/azure-cli
Download-Size: 2608 B
APT-Sources: http://archive.ubuntu.com/ubuntu hirsute/universe amd64 Packages
Description: Azure Command-Line Interface (CLI)

This Azure CLI from Ubuntu universe repo is very old and contains bugs.

Official Azure CLI focal from Microsoft Linux repo doesn't work on hirsute

Besides, even if the user installs with https://aka.ms/InstallAzureCLIDeb which automatically falls back to focal (#19313 (comment)), the focal package doesn't work correctly on hirsute (#18703).

Change

This PR builds a deb packaging for hirstute.

[yonzhan]

Packaging

[jiasli]

Ubuntu 21.04 Hirsute Hippo support will be release in Azure CLI 2.28.0 on 09/07/2021.

[jiasli]

Ubuntu 21.04 Hirsute Hippo package has been released:

• https://packages.microsoft.com/repos/azure-cli/dists/hirsute/
• https://packages.microsoft.com/repos/azure-cli/pool/main/a/azure-cli/azure-cli_2.28.0-1~hirsute_all.deb