AppWidgetServiceImpl: Use enforceCallingOrSelfPermission for checking DUMP

Use enforceCallingOrSelfPermission() for throwing a security exception
rather than creating the security exception ourselves. This has the
advantage that the exception is in a well known format expected by
the CTS test android.security.cts.ServicePermissionsTest#testDumpProtected

Bug: 17165920
Change-Id: I7d3c2d2a0852a490fe1d553cd81d1efc79d2fec3
diff --git a/services/appwidget/java/com/android/server/appwidget/AppWidgetServiceImpl.java b/services/appwidget/java/com/android/server/appwidget/AppWidgetServiceImpl.java
index 7f7e5c3..06c4cfd 100644
--- a/services/appwidget/java/com/android/server/appwidget/AppWidgetServiceImpl.java
+++ b/services/appwidget/java/com/android/server/appwidget/AppWidgetServiceImpl.java
@@ -440,12 +440,10 @@
 
     @Override
     public void dump(FileDescriptor fd, PrintWriter pw, String[] args) {
-        if (mContext.checkCallingOrSelfPermission(android.Manifest.permission.DUMP)
-                != PackageManager.PERMISSION_GRANTED) {
-            throw new SecurityException("Permission Denial: can't dump from from pid="
-                    + Binder.getCallingPid()
-                    + ", uid=" + Binder.getCallingUid());
-        }
+        mContext.enforceCallingOrSelfPermission(android.Manifest.permission.DUMP,
+                                                "Permission Denial: can't dump from from pid="
+                                                + Binder.getCallingPid()
+                                                + ", uid=" + Binder.getCallingUid());
 
         synchronized (mLock) {
             int N = mProviders.size();