Azure Keyvault secret reference for application insight not resolving within Azure Function via environment variable.

I provided the Azure Application Insights connection string as a Key Vault reference through the environment variable named `APPLICATIONINSIGHTS_CONNECTION_STRING`. The setup is able to connect to the Key Vault, as shown in the image below.

However, there is still one issue: although everything is being logged in the Application Insights log tab of the Azure Function, it continues to provide an option to configure Application Insights, even though it is already configured.

As a workaround after Terraform deployment, I have to provide the Application Insights connection string in plain text. After it shows it's connected with Application Insights, then again, I reference the Key Vault, and everything works as expected.

Start by reviewing the Azure Function configuration for the APPLICATIONINSIGHTS_CONNECTION_STRING environment variable and the Terraform deployment that creates the Key Vault reference. Verify why Application Insights still appears unconfigured when logs are present; done means the Key Vault reference is recognized without temporarily supplying the connection string in plain text.

Written by the indexing model from the issue text.