add ueventd to shutdown critial process

- In some devices, some drivers still try to load firmware while shutting
  down, and crashes the kernel. So keep ueventd to prevent such case.

bug: 38203024
Test: reboots

(cherry picked from commit 7264bee975bdd35eac256e4939fa7dfd8962c2ac)

Change-Id: Ifc725f906de01eba552c782b8ec0d7bd11d089d0
diff --git a/init/reboot.cpp b/init/reboot.cpp
index c997519..aac1b5c 100644
--- a/init/reboot.cpp
+++ b/init/reboot.cpp
@@ -331,7 +331,7 @@
     // keep debugging tools until non critical ones are all gone.
     const std::set<std::string> kill_after_apps{"tombstoned", "logd", "adbd"};
     // watchdogd is a vendor specific component but should be alive to complete shutdown safely.
-    const std::set<std::string> to_starts{"watchdogd", "vold"};
+    const std::set<std::string> to_starts{"watchdogd", "vold", "ueventd"};
     ServiceManager::GetInstance().ForEachService([&kill_after_apps, &to_starts](Service* s) {
         if (kill_after_apps.count(s->name())) {
             s->SetShutdownCritical();