[installer] Create a blank grubenv if doesn't exist

[nazariig]

GRUB environment file is neither generated when SONiC is installed from ONiE nor when GRUB starts boot chain sequence

https://github.com/sonic-net/sonic-buildimage/blob/202305/installer/default_platform.conf#L506

    cat <<EOF >> $grub_cfg
if [ -s \$prefix/grubenv ]; then
    load_env
fi
if [ "\${saved_entry}" ]; then
    set default="\${saved_entry}"
fi
if [ "\${next_entry}" ]; then
    set default="\${next_entry}"
    unset next_entry
    save_env next_entry
fi
if [ "\${onie_entry}" ]; then
    set next_entry="\${default}"
    set default="\${onie_entry}"
    unset onie_entry
    save_env onie_entry next_entry
fi
EOF

The GRUB environment file is being regenerated (if not present) each time after system cold reboot, when SONiC reboot script is being called

https://github.com/sonic-net/sonic-utilities/blob/202305/scripts/reboot#L152

# Verify the next image by sonic-installer
local message=$(sonic-installer verify-next-image 2>&1)
if [ $? -ne 0 ]; then
    VERBOSE=yes debug "Failed to verify next image: ${message}"
    exit ${EXIT_SONIC_INSTALLER_VERIFY_REBOOT}
fi

In fact, GRUB environment list command is responsible for regeneration

root@r-anaconda-15:/home/admin# ls /host/grub/
fonts  grub.cfg  grubenv  i386-pc  locale
root@r-anaconda-15:/home/admin# rm -f /host/grub/grubenv
root@r-anaconda-15:/home/admin# ls /host/grub/
fonts  grub.cfg  i386-pc  locale
root@r-anaconda-15:/home/admin# grub-editenv /host/grub/grubenv list
root@r-anaconda-15:/home/admin# ls /host/grub/
fonts  grub.cfg  grubenv  i386-pc  locale

Why I did it

• To fix BIOS firmware update after fresh image installation from ONiE

Work item tracking

• N/A

How I did it

• Initialized empty GRUB environment file after ONiE installation

How to verify it

1. Install image from ONiE
2. Run BIOS firmware upgrade

Which release branch to backport (provide reason below if selected)

• 201811
• 201911
• 202006
• 202012
• 202106
• 202111
• 202205
• 202211
• 202305

Tested branch (Please provide the tested image version)

• 202305 commit 688245a

Description for the changelog

• N/A

Link to config_db schema for YANG module changes

• N/A

A picture of a cute animal (not mandatory but encouraged)

      .---.        .-----------
     /     \  __  /    ------
    / /     \(  )/    -----
   //////   ' \/ `   ---
  //// / // :    : ---
 // /   /  /`    '--
//          //..\\
       ====UU====UU====
           '//||\\`
             ''``

[nazariig]

/azpw run

[mssonicbld]

/AzurePipelines run

[azure-pipelines]

You have several pipelines (over 10) configured to build pull requests in this repository. Specify which pipelines you would like to run by using /azp run [pipelines] command. You can specify multiple pipelines using a comma separated list.

[nazariig]

/azpw run Azure.sonic-buildimage

[mssonicbld]

/AzurePipelines run Azure.sonic-buildimage

[azure-pipelines]

Azure Pipelines successfully started running 1 pipeline(s).

[dgsudharsan]

@StormLiangMS Tested on top of 202305 commit 688245a

[saiarcot895]

What was the issue in #17216? What is being fixed here?

[nazariig]

What was the issue in #17216? What is being fixed here?

@saiarcot895 this fix includes a secure upgrade case

[mssonicbld]

Cherry-pick PR to 202305: #17525

[mssonicbld]

Cherry-pick PR to 202311: #17965