container name not supported with upper case (Azure#20012)

TargetContainerName - This name may only contain lowercase letters, numbers, and hyphens, and must begin with a letter or a number. Each hyphen must be preceded and followed by a non-hyphen character. The name must also be between 3 and 63 characters long.

the command "Backup-AzApiManagement" fails if TargetContainerName has value in upper case

Author: SherrySahni

src/ApiManagement/ApiManagement/help/Backup-AzApiManagement.md

@@ -33,7 +33,7 @@ This cmdlet stores the backup as an Azure Storage blob.
 New-AzStorageAccount -StorageAccountName "ContosoStorage" -Location $location -ResourceGroupName "ContosoGroup02" -Type Standard_LRS
 $storageKey = (Get-AzStorageAccountKey -ResourceGroupName "ContosoGroup02" -StorageAccountName "ContosoStorage")[0].Value
 $storageContext = New-AzStorageContext -StorageAccountName "ContosoStorage" -StorageAccountKey $storageKey
-Backup-AzApiManagement -ResourceGroupName "ContosoGroup02" -Name "ContosoApi" -StorageContext $StorageContext -TargetContainerName "ContosoBackups" -TargetBlobName "ContosoBackup.apimbackup"
+Backup-AzApiManagement -ResourceGroupName "ContosoGroup02" -Name "ContosoApi" -StorageContext $StorageContext -TargetContainerName "contosobackups" -TargetBlobName "contosobackups.apimbackup"
 ```
 
 ### Example 2: Back up using Managed Identity