Command func azure functionapp logstream fails on new Python apps

[ggailey777]

Linux Consumption apps (e.g. most Python apps) require you to use the func azure functionapp logstream <APP_NAME> --browser to open a new AI Logstream window in the Azure portal because of #2138.

However, this command seems to require the deprecated APPINSIGHTS_INSTRUMENTATIONKEY setting, which was are no longer setting for new apps (because it's deprecated).

Repro: create a new Linux app on a Consumption plan and run func azure functionapp logstream <APP_NAME> --browser
Expected: Logstream opens in a new browser window.
Actual: Error is returned: Missing APPINSIGHTS_INSTRUMENTATIONKEY App Setting. Please make sure you have Application Insights configured with you function app.

The current func azure functionapp logstream experience is currently broken in the Python quickstart.