feat(intellij): Add intellij as liveness probe

Related to eclipse-che#17790

Change-Id: I07b6c4b02bcb1e7fd9725e2e640f7c7e0d66aee2
Signed-off-by: Florent Benoit <fbenoit@redhat.com>

assembly/assembly-wsmaster-war/src/main/webapp/WEB-INF/classes/che/che.properties

@@ -163,7 +163,7 @@ che.workspace.server.ping_success_threshold=1
 che.workspace.server.ping_interval_milliseconds=3000
 
 # List of servers names which require liveness probes
-che.workspace.server.liveness_probes=wsagent/http,exec-agent/http,terminal,theia,jupyter,dirigible,cloud-shell
+che.workspace.server.liveness_probes=wsagent/http,exec-agent/http,terminal,theia,jupyter,dirigible,cloud-shell,intellij
 
 # Limit size of the logs collected from single container that can be observed by che-server when
 # debugging workspace startup.