rhui(gcp): add SAP RHEL 8.10 client

Add a dedicated entry for SAP RHEL 8.10 on GCP due to the same reasons
as with other cloud providers - 8.10 is the last RHEL8 release, thus,
there are no content channels. A dedicated client is introduced,
providing SAP systems with GA content.

repos/system_upgrade/common/libraries/rhui.py

@@ -323,6 +323,10 @@ def mk_rhui_setup(clients=None, leapp_pkg='', mandatory_files=None, optional_fil
                       mandatory_files=[('leapp-google-sap.repo', YUM_REPOS_PATH)],
                       files_supporting_client_operation=['leapp-google-sap.repo'],
                       os_version='8', content_channel=ContentChannel.E4S),
+        mk_rhui_setup(clients={'google-rhui-client-rhel810-sap'}, leapp_pkg='leapp-rhui-google-sap',
+                      mandatory_files=[('leapp-google-sap.repo', YUM_REPOS_PATH)],
+                      files_supporting_client_operation=['leapp-google-sap.repo'],
+                      os_version='8.10', content_channel=ContentChannel.GA),
         mk_rhui_setup(clients={'google-rhui-client-rhel9-sap'}, leapp_pkg='leapp-rhui-google-sap',
                       mandatory_files=[('leapp-google-sap.repo', YUM_REPOS_PATH)],
                       files_supporting_client_operation=['leapp-google-sap.repo'],