Set Bluetooth adapter to PowerOff mode when turnoff with airplane on

Currently, when airplane mode was on and BT was on, turning BT off
moved BT to hotoff state. This fix moves BT all the way to Poweroff
state to have better power performance.
bug 5854282

Change-Id: I7ba41797a46a81ddb3a576453f2a8303b5eed525
diff --git a/core/java/android/server/BluetoothService.java b/core/java/android/server/BluetoothService.java
index 94fbbc8..fecc8f9 100755
--- a/core/java/android/server/BluetoothService.java
+++ b/core/java/android/server/BluetoothService.java
@@ -1706,7 +1706,7 @@
     }
 
     /* Returns true if airplane mode is currently on */
-    private final boolean isAirplaneModeOn() {
+    /*package*/ final boolean isAirplaneModeOn() {
         return Settings.System.getInt(mContext.getContentResolver(),
                 Settings.System.AIRPLANE_MODE_ON, 0) == 1;
     }