Storage blob public access needs to be disabled when creating a Function App

[im-samz]

A new Azure policy is rolling out to block Storage accounts created with allowBlobPublicAccess: true.

The Azure Functions extension provides two ways to create a function app:

1. Create new Function App in Azure --> creates a storage account behind the scenes
2. Create new Function App in Azure (advanced) --> you specify a name for the storage account

In both scenarios, we need to modify the ARM template creating the Azure Storage account to include the following resource property:

• allowBlobPublicAccess: false

Only by doing so will the create pass validation.

I suspect the policy is rolling out to more Microsoft subscriptions, so more MS employees will hit this.

cc @nturinski