Azure - do not use 0 zone or empty string for zone when creating PVs

test/e2e/framework/providers/azure/azure.go

@@ -72,10 +72,14 @@ func (p *Provider) CreatePD(zone string) (string, error) {
 		PVCName:            pdName,
 		SizeGB:             1,
 		Tags:               nil,
-		AvailabilityZone:   zone,
 		DiskIOPSReadWrite:  "",
 		DiskMBpsReadWrite:  "",
 	}
+
+	// do not use blank zone definition
+	if len(zone) > 0 && zone != "0" {
+		volumeOptions.AvailabilityZone = zone
+	}
 	return p.azureCloud.CreateManagedDisk(volumeOptions)
 }