Issue while creating a self-signed certificate using Azure Keyvault with azure-cli

### **This is autogenerated. Please review and update as needed.**

## Describe the bug

**Command Name**
`az keyvault certificate create`

**Errors:**
```
Expecting property name enclosed in double quotes: line 2 column 3 (char 4)
```

## To Reproduce:
Steps to reproduce the behavior.

- `az keyvault certificate create --vault-name my-random-keyvault-name -n cert1 -p "$(az keyvault certificate get-default-policy)"`

## Expected Behavior
That it would generate a selfsigned certificate

## Environment Summary
```
Linux-4.4.0-18362-Microsoft-x86_64-with-debian-stretch-sid
Python 3.6.5
Shell: bash

azure-cli 2.0.68

Extensions:
azure-firewall 0.1.2
interactive 0.4.3

```
## Additional Context