[ReleasePR consumption] [Hub Generated] Review request for Microsoft.Consumption to add version stable/2021-05-01 (#1871)

Create to sync Azure/azure-rest-api-specs#15648
[ReCreate this PR](https://github.com/azure-resource-manager-schemas/compare/main...AzureSDKAutomation:sdkAuto/consumption?expand=1)

Author: msftbot[bot]