Clarify use of Update-AzStorageAccountADObjectPassword

Just to be clear on the intended use of this command, you're always supposed to run it twice? The instructions on Microsoft Docs (https://docs.microsoft.com/en-us/azure/storage/files/storage-files-identity-ad-ds-update-password) seem to indicate that you just need to run the command once. However, the comment block for the command seems to indicate that you're actually supposed to rotate from kerb1 to kerb2 then back to kerb1 within the span of a "several" hours. Presumably this is achieved by running the command twice.

E.g.
```
Update-AzStorageAccountADObjectPassword -RotateToKerbKey kerb2 -ResourceGroupName "" -StorageAccountName ""
Start-Sleep -Seconds 14400
Update-AzStorageAccountADObjectPassword -RotateToKerbKey kerb1 -ResourceGroupName "" -StorageAccountName ""
```