Default firmware override

[mondalaci]

The default firmware is bundled with Agent and can only be changed by releasing a new Agent version.

This can sometimes be a problem. For example, Agent 5.0.0 is currently the latest release, which bundles firmware 12.0.0, which contains some regressions. I want to force Agent 5.0.0 to use the latest firmware, 12.0.1, which fixes the regressions, and offer it as the default firmware instead of the bundled firmware.

I propose a firmware-overrides.json file stored in the repo that would contain the following for this case:

{
    "5.0.0": "12.0.1"
}

Before displaying the firmware update notification, Agent must read firmware-overrides.json and fetch the relevant firmware version or use the bundled version if GitHub timeouts.