Report the retained service ID after the combined teardown check

tools/chatgui-android/app/src/main/java/com/utun/chat/data/CallService.kt

@@ -55,7 +55,7 @@ class CallService : Service() {
             pendingCleanup?.shutdown()
             TelecomCallManager.requireReleased()
             check(pendingCleanup == null) {
-                val message = "Call service cleanup still pending id=${previous.callId}"
+                val message = "Call service cleanup still pending id=${pendingCleanup?.callId}"
                 LogManager.addLog("ERROR", "CallService", message)
                 message
             }