servicemanager: log isolated app violation

Bug: 286851628
Test: servicemanager_test
Change-Id: I3e95ce54418f36918b35909b986be3a23a55ac57
diff --git a/cmds/servicemanager/ServiceManager.cpp b/cmds/servicemanager/ServiceManager.cpp
index e30cbd5..44ccf50 100644
--- a/cmds/servicemanager/ServiceManager.cpp
+++ b/cmds/servicemanager/ServiceManager.cpp
@@ -291,6 +291,8 @@
         service = &(it->second);
 
         if (!service->allowIsolated && is_multiuser_uid_isolated(ctx.uid)) {
+            LOG(WARNING) << "Isolated app with UID " << ctx.uid << " requested '" << name
+                         << "', but the service is not allowed for isolated apps.";
             return nullptr;
         }
         out = service->binder;