Add skip_build_key_vault_create to skip build Keyvault create during window builds

[garimakhulbe02]

This PR is add this attribute #357

New attribute/input skip_build_key_vault_create in packer config to skip Keyvault deployment during packer build for windows images. Packer does two ARM deployments during build. First deployment for Keyvault to save WinRM certificate and second deployment for build VM. This attribute will give an option to skip this build Keyvault deployment during build.

[hashicorp-cla]

All committers have signed the CLA.

[garimakhulbe02]

@JenGoldstrich @nywilken please take a look. thank you.

[JenGoldstrich]

Hey @garimakhulbe02 thanks for opening this PR, can you post the custom_script and user_data example to load the WinRM certificate that you mentioned in the issue, would be helpful so that I can quickly test this feature, and also add to document how to use this feature, as the new field won't work otherwise as I understand it

[garimakhulbe02]

@JenGoldstrich updated PR with example. please take a look. thanks.

[JenGoldstrich]

Hey @garimakhulbe02 I emailed you too but just to have the context here for any other contributors or readers I am running into the following error

```WinRM firewall exception will not work since one of the network \r\nconnection types on this machine is set to Public. Change the network connection type to either Domain or Private and \r\ntry again. 

from the VM extension when trying to deploy the VM template with the provided configuration, can you provide me the template you use to build this feature so I can see what network config I'm missing to make this work

[garimakhulbe02]

Hey @garimakhulbe02 I emailed you too but just to have the context here for any other contributors or readers I am running into the following error

```WinRM firewall exception will not work since one of the network \r\nconnection types on this machine is set to Public. Change the network connection type to either Domain or Private and \r\ntry again. 

from the VM extension when trying to deploy the VM template with the provided configuration, can you provide me the template you use to build this feature so I can see what network config I'm missing to make this work

let me check. will send you by tomorrow EOD.