Merge "Fix Quiescent Reboot Reason" am: 850866e94a am: 933dacacf8 am: dc2d21b93d

Original change: https://android-review.googlesource.com/c/platform/frameworks/base/+/1751962

Change-Id: I418d770eb17a316e6267d1b22a5b951f58b8f0e5

services/core/java/com/android/server/power/PowerManagerService.java

@@ -4087,7 +4087,10 @@ public final class PowerManagerService extends SystemService
         if (sQuiescent) {
             // Pass the optional "quiescent" argument to the bootloader to let it know
             // that it should not turn the screen/lights on.
-            reason = reason + ",quiescent";
+            if (reason != ""){
+                reason += ",";
+            }
+            reason = reason + "quiescent";
         }
 
         SystemProperties.set("sys.powerctl", "reboot," + reason);