Merge "Ensure settings maintains its Bluetooth device inquiry state"

src/com/android/settings/bluetooth/DeviceListPreferenceFragment.java

@@ -229,15 +229,19 @@ public abstract class DeviceListPreferenceFragment extends
     @VisibleForTesting
     void enableScanning() {
         // BluetoothAdapter already handles repeated scan requests
+        if (!mScanEnabled) {
             startScanning();
             mScanEnabled = true;
         }
+    }
 
     @VisibleForTesting
     void disableScanning() {
+        if (mScanEnabled) {
             stopScanning();
             mScanEnabled = false;
         }
+    }
 
     @Override
     public void onScanningStateChanged(boolean started) {