Test Fix

1. Fix a test logic for Bug 1561: VM not become ready after restarting. (https://github.com/WindowsAzure/azure-sdk-tools/issues/1561)

Updated test code stops from ready state.


2. Fix 409 issue: Add retrying logic for bug 1813 (https://github.com/WindowsAzure/azure-sdk-tools/issues/1813)