Setting secret in KV fails for starting with special chars

[santhoshb-msft]

Describe the bug

To Reproduce Steps to reproduce the behavior:

1. Set a KV secret with --__
2. Observe below error

Expected behavior A clear and concise description of what you expected to happen.

Screenshots If applicable, add screenshots to help explain your problem.

Environment (please complete the following information):

• Are you using the CloudShell?
• If not using the CloudShell:
  • OS: [e.g. iOS]
  • PowerShell version
  • Modules installed

Additional context Add any other context about the problem here.