{Core} Fix: In Cloud Shell, cross-tenant authentication fails for user or Service Principal account

[jiasli]

Description

In Cloud Shell, even if az login is run with user or Service Principal account, subsequent commands involving cross-tenant authentication fails:

$ az network vnet peering create --name myVnetAToMyVnetB --resource-group myResourceGroupA --vnet-name myVnetA --remote-vnet /subscriptions/414af076-009b-4282-9a0a-acf75bcb037e/resourceGroups/myResourceGroupB/providers/Microsoft.Network/VirtualNetworks/myVnetB --allow-vnet-access
Cross-tenant authentication is not supported by managed identity and Cloud Shell. Please run `az login` with 
a user account or a service principal.

Cause

This bug was introduced by #16797 where only in_cloud_console() is checked:

azure-cli/src/azure-cli-core/azure/cli/core/_profile.py

Lines 564 to 566 in 039fa21

	if external_tenants_info and (identity_type or in_cloud_console()):
	raise CLIError("Cross-tenant authentication is not supported by managed identity and Cloud Shell. "
	"Please run `az login` with a user account or a service principal.")

In fact, _CLOUD_SHELL_ID (cloudShellID) should also be checked so that the error is only raised for Cloud Shell's Managed Identity account, instead of user or Service Principal account.

Testing guide

In Cloud Shell, run

az login
# Replace `414af076-009b-4282-9a0a-acf75bcb037e` with your own subscription ID in another tenant
az network vnet peering create --name myVnetAToMyVnetB --resource-group myResourceGroupA --vnet-name myVnetA --remote-vnet /subscriptions/414af076-009b-4282-9a0a-acf75bcb037e/resourceGroups/myResourceGroupB/providers/Microsoft.Network/VirtualNetworks/myVnetB --allow-vnet-access

[yonzhan]

Core

[yonzhan]

LGTM