Merge pull request kubernetes#101550 from andyzhangx/automated-cherry…

…-pick-of-#100731-upstream-release-1.20

Automated cherry pick of kubernetes#100731: Normalize share name to not include capital letters

pkg/volume/azure_file/azure_provision.go

@@ -198,9 +198,10 @@ func (a *azureFileProvisioner) Provision(selectedNode *v1.Node, allowedTopologie
 	}
 
 	if shareName == "" {
-		// File share name has a length limit of 63, and it cannot contain two consecutive '-'s.
+		// File share name has a length limit of 63, it cannot contain two consecutive '-'s, and all letters must be lower case.
 		name := util.GenerateVolumeName(a.options.ClusterName, a.options.PVName, 63)
 		shareName = strings.Replace(name, "--", "-", -1)
+		shareName = strings.ToLower(shareName)
 	}
 
 	if resourceGroup == "" {