[ReleasePR chaos] Update Microsoft.Chaos API Version 2021-09-15-preview (#1982)
[ReleasePR chaos] Update Microsoft.Chaos API Version 2021-09-15-preview (#1982)

Create to sync https://github.com/Azure/azure-rest-api-specs/pull/16480
[ReCreate this PR](https://github.com/azure-resource-manager-schemas/compare/main...AzureSDKAutomation:sdkAuto/chaos?expand=1)
Azure/azure-resource-manager-schemas,Azure/azure-resource-manager-schemas,Azure/azure-resource-manager-schemas,Azure/azure-resource-manager-schemas