Optional parameters are no longer optional

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Run 'az keyvault certificate show-deleted' command, but it keeps asking those optional parameters. The doc said those are optional but does not look optional anymore. Is it the bug in az keyvault module? or, an incorrect information on the document?

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#### Document Details

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* ID: a9c661d7-bf43-5354-015e-3859f30a42a2
* Version Independent ID: fa69e552-5904-ce97-d02c-915c819bdde1
* Content: [az keyvault certificate](https://docs.microsoft.com/en-us/cli/azure/keyvault/certificate?view=azure-cli-latest)
* Content Source: [latest/docs-ref-autogen/keyvault/certificate.yml](https://github.com/MicrosoftDocs/azure-docs-cli/blob/master/latest/docs-ref-autogen/keyvault/certificate.yml)
* Service: **key-vault**
* GitHub Login: @rloutlaw
* Microsoft Alias: **routlaw**