添加系统属性,通过监听插拔广播判断当前有无OTG U盘插入

--- a/frameworks/base/services/core/java/com/android/server/policy/PhoneWindowManager.java
+++ b/frameworks/base/services/core/java/com/android/server/policy/PhoneWindowManager.java
@@ -246,6 +246,7 @@ import java.security.InvalidAlgorithmParameterException;
 import java.security.NoSuchAlgorithmException;
 import java.security.NoSuchProviderException;
 import java.security.KeyPairGenerator;
+import android.hardware.usb.UsbManager; //yim add
 /**
 /**
  * WindowManagerPolicy implementation for the Android phone UI.  This
@@ -2115,6 +2116,8 @@ public class PhoneWindowManager implements WindowManagerPolicy {
+               filter.addAction(UsbManager.ACTION_USB_DEVICE_ATTACHED);//yim add
+               filter.addAction(UsbManager.ACTION_USB_DEVICE_DETACHED);//yim add
         filter.addAction(Intent.ACTION_DOCK_EVENT);
         Intent intent = contex