Make AtomicFile a public API.  It's about time!

Change-Id: Ib34e294747405b7ab709cb0bbb2d9a0cc80ce86a
diff --git a/services/java/com/android/server/net/NetworkStatsCollection.java b/services/java/com/android/server/net/NetworkStatsCollection.java
index 9ddf011..60666b4 100644
--- a/services/java/com/android/server/net/NetworkStatsCollection.java
+++ b/services/java/com/android/server/net/NetworkStatsCollection.java
@@ -29,8 +29,8 @@
 import android.net.NetworkTemplate;
 import android.net.TrafficStats;
 import android.text.format.DateUtils;
+import android.util.AtomicFile;
 
-import com.android.internal.os.AtomicFile;
 import com.android.internal.util.FileRotator;
 import com.android.internal.util.IndentingPrintWriter;
 import com.android.internal.util.Objects;