Init remove direct calls to light sys nodes.

These are halified. Instead launch blank_screen which
does the same task w/o init itself having binder
dependencies.

Bug: 70846424
Test: manual + reboot appears similar
Change-Id: If8b2a56cbc31077122ea81406721b06034e4498f
diff --git a/init/reboot.cpp b/init/reboot.cpp
index 21086dc..a88a42d 100644
--- a/init/reboot.cpp
+++ b/init/reboot.cpp
@@ -137,25 +137,12 @@
 
 // Turn off backlight while we are performing power down cleanup activities.
 static void TurnOffBacklight() {
-    static constexpr char OFF[] = "0";
-
-    android::base::WriteStringToFile(OFF, "/sys/class/leds/lcd-backlight/brightness");
-
-    static const char backlightDir[] = "/sys/class/backlight";
-    std::unique_ptr<DIR, int (*)(DIR*)> dir(opendir(backlightDir), closedir);
-    if (!dir) {
+    Service* service = ServiceList::GetInstance().FindService("blank_screen");
+    if (service == nullptr) {
+        LOG(WARNING) << "cannot find blank_screen in TurnOffBacklight";
         return;
     }
-
-    struct dirent* dp;
-    while ((dp = readdir(dir.get())) != nullptr) {
-        if (((dp->d_type != DT_DIR) && (dp->d_type != DT_LNK)) || (dp->d_name[0] == '.')) {
-            continue;
-        }
-
-        std::string fileName = StringPrintf("%s/%s/brightness", backlightDir, dp->d_name);
-        android::base::WriteStringToFile(OFF, fileName);
-    }
+    service->Start();
 }
 
 static void ShutdownVold() {
@@ -316,8 +303,6 @@
     std::vector<MountEntry> block_devices;
     std::vector<MountEntry> emulated_devices;
 
-    TurnOffBacklight();  // this part can take time. save power.
-
     if (runFsck && !FindPartitionsToUmount(&block_devices, &emulated_devices, false)) {
         return UMOUNT_STAT_ERROR;
     }
@@ -397,6 +382,11 @@
         }
     }
 
+    // remaining operations (specifically fsck) may take a substantial duration
+    if (cmd == ANDROID_RB_POWEROFF || is_thermal_shutdown) {
+        TurnOffBacklight();
+    }
+
     Service* bootAnim = ServiceList::GetInstance().FindService("bootanim");
     Service* surfaceFlinger = ServiceList::GetInstance().FindService("surfaceflinger");
     if (bootAnim != nullptr && surfaceFlinger != nullptr && surfaceFlinger->IsRunning()) {