Add terminal info to flutter command event

[eliasyishak]

Related to tracker issue:

• ☂️ package:unified_analytics implementation in flutter tool flutter/flutter#128251

Closes:

• Create a user property for commandHasTerminal #197

While migrating the Usage.command static method, includes the commandHasTerminal parameter, I realized that it probably makes sense to include it with the previously migrated CommandResult event.

This new event will now let us record which flutter command was run, while also keeping track of whether the invocation included a terminal.

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[eliasyishak]

@leighajarett is it actually necessary to have this field as a user property? After looking through flutter code, we are only sending this along with each command event

It looks like the only two fields we send with each event is for the channel and OS, which we are currently doing now

[eliasyishak]

The newly added parameter

[leighajarett]

LGTM