Automatic merge from submit-queue (batch tested with PRs 38638, 38334)
Remove Azure Subnet RouteTable check
**What this PR does / why we need it**:
PR Removes the subnet configuration check for Azure cloudprovider. The subnet check ensures that the subnet is associated with the Route Table. However if the VNET is in a different Azure Resource Group then the check fails, even if the subnet is already valid. This a stop gap fix, to allow Kubernetes to be deployed to Custom VNETs in Azure, that may reside in a different resource group to the cluster.
fixes#38134
@colemickens