Add Data Disk Latency

[adammazouz]

Azure has introduced latency metrics for managed disks.

https://azure.microsoft.com/en-us/updates/latency-metrics-for-azure-disks-and-performance-metrics-for-temporary-disks-on-azure-virtual-machines/

Data Disk Latency (Preview): The average time to complete IOs during the monitoring for the data disk. Values are in miliseconds.