[Bug] more "///" are generated by autorest.powershell

[YanaXu]

In this Azure/azure-powershell PR and file src/CognitiveServices/CognitiveServices.Management.Sdk/Generated/ICognitiveServicesManagementClient.cs, additional "///" are generated.

[dolauli]

Hi Yabo Hu (@VeryEarly), I believe the root cause of the issue is that some comments were not updated when implementing the feature to break long comments into multiple lines. Here are some examples:
https://github.com/Azure/autorest.powershell/blob/main/powershell/plugins/sdk-tweak-model.ts#L442
https://github.com/Azure/autorest.powershell/blob/main/powershell/plugins/sdk-tweak-model.ts#L451