Add a UDEV rule in azure disk encryption on Linux (#1287)
Add a UDEV rule in azure disk encryption on Linux (#1287)

Recently we are trying to do azure disk encryption on Ubuntu & RedHat and found that a UDEV rule is missing, the new UDEV rule is like following in `/etc/udev/rules.d/66-azure-storage.rules`
```
ATTRS{device_id}=="?00000001-0001-*", ENV{fabric_name}="BEK", GOTO="azure_names"
```
After disk encryption:
 - Without this UDEV rule
```
$ sudo tree /dev/disk/azure
âââ resource -> ../../sdb
âââ resource-part1 -> ../../sdb1
âââ root -> ../../sda
âââ root-part1 -> ../../sda1
âââ scsi1
    âââ lun0 -> ../../../sdd
```
 - With this UDEV rule
```
$ sudo tree /dev/disk/azure
âââ BEK -> ../../sdc
âââ resource -> ../../sdb
âââ resource-part1 -> ../../sdb1
âââ root -> ../../sda
âââ root-part1 -> ../../sda1
âââ scsi1
    âââ lun0 -> ../../../sdd
```

All azure os, resource and bek disks should be under `/dev/disk/azure` directory, that's a rule.
The item `BEK -> ../../sdc` is very important in kubernetes, without this item, new data disk could not be recognized, details info could be found here: https://github.com/kubernetes/kubernetes/issues/66443#issuecomment-406765240
rjschwei/WALinuxAgent,hglkrijger/WALinuxAgent,Azure/WALinuxAgent,hglkrijger/WALinuxAgent,rjschwei/WALinuxAgent,Azure/WALinuxAgent