Add northeastus5 region mapping to backup module

Author: prog-rajkamal

src/azure-cli/azure/cli/command_modules/backup/custom.py

@@ -87,6 +87,7 @@
     "koreasouth": "koreacentral",
     "malaysiasouth": "japanwest",
     "northcentralus": "southcentralus",
+    "northeastus5": "centralus",
     "northeurope": "westeurope",
     "norwayeast": "norwaywest",
     "norwaywest": "norwayeast",