Fix dumpPowerState method

dumpPowerState method shows the current power manger service state but,
BUTTON_BRIGHT_BIT is omitted.

Add a routine of checking BUTTON_BRIGHT_BIT
Signed-off-by: jaiyoung.park <jaiyoung.park@lge.com>

Change-Id: I00484fb384963bafdc58ce89b3251a1f5585d992

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

@@ -1103,6 +1103,8 @@ public class PowerManagerService extends IPowerManager.Stub
                         ? "SCREEN_BRIGHT_BIT " : "")
                 + (((state & SCREEN_ON_BIT) != 0)
                         ? "SCREEN_ON_BIT " : "")
+                + (((state & BUTTON_BRIGHT_BIT) != 0)
+                        ? "BUTTON_BRIGHT_BIT " : "")
                 + (((state & BATTERY_LOW_BIT) != 0)
                         ? "BATTERY_LOW_BIT " : "");
     }