Make USB mass storage hide keyguard when shown.

Change-Id: I4d3592ade43c8b2e87768a55ba0fafb8e189a1fc
diff --git a/packages/SystemUI/src/com/android/systemui/usb/UsbStorageActivity.java b/packages/SystemUI/src/com/android/systemui/usb/UsbStorageActivity.java
index 29df28e..d024dd0 100644
--- a/packages/SystemUI/src/com/android/systemui/usb/UsbStorageActivity.java
+++ b/packages/SystemUI/src/com/android/systemui/usb/UsbStorageActivity.java
@@ -46,6 +46,7 @@
 import android.widget.TextView;
 import android.view.View;
 import android.view.Window;
+import android.view.WindowManager;
 import android.util.Log;
 
 import java.util.List;
@@ -102,6 +103,11 @@
         requestWindowFeature(Window.FEATURE_INDETERMINATE_PROGRESS);
         setProgressBarIndeterminateVisibility(true);
 
+        getWindow().addFlags(WindowManager.LayoutParams.FLAG_DISMISS_KEYGUARD);
+        if (Environment.isExternalStorageRemovable()) {
+            getWindow().addFlags(WindowManager.LayoutParams.FLAG_SHOW_WHEN_LOCKED);
+        }
+
         setTitle(getString(com.android.internal.R.string.usb_storage_activity_title));
 
         setContentView(com.android.internal.R.layout.usb_storage_activity);