Cover upgrades RHEL 8 to RHEL 9 using RHUI on Alibaba cloud

Note the repomap.json file does not cover yet mapping of repositories
between RHEL 8 and RHEL 9 for aarch64 (ARM). This will be covered
by further update of the file.

repos/system_upgrade/common/libraries/rhui.py

@@ -481,6 +481,17 @@ def mk_rhui_setup(clients=None, leapp_pkg='', mandatory_files=None, optional_fil
                 ('leapp-google-sap.repo', YUM_REPOS_PATH)
             ],
         },
+        'alibaba': {
+            'src_pkg': 'aliyun_rhui_rhel8',
+            'target_pkg': 'aliyun_rhui_rhel9',
+            'leapp_pkg': 'leapp-rhui-alibaba',
+            'leapp_pkg_repo': 'leapp-alibaba.repo',
+            'files_map': [
+                ('content.crt', RHUI_PKI_PRODUCT_DIR),
+                ('key.pem', RHUI_PKI_DIR),
+                ('leapp-alibaba.repo', YUM_REPOS_PATH)
+            ],
+        },
     },
 }