Move NetworkPolicyEditor from Settings packge to settingslib.

Change-Id: I3a2f69c73d983643e65a0d4266cb98a203d5a813
diff --git a/src/com/android/settings/DataUsageSummary.java b/src/com/android/settings/DataUsageSummary.java
index 7a5a60a..a10e1a8 100644
--- a/src/com/android/settings/DataUsageSummary.java
+++ b/src/com/android/settings/DataUsageSummary.java
@@ -134,7 +134,6 @@
 import com.android.settings.net.ChartData;
 import com.android.settings.net.ChartDataLoader;
 import com.android.settings.net.DataUsageMeteredSettings;
-import com.android.settings.net.NetworkPolicyEditor;
 import com.android.settings.net.SummaryForAllUidLoader;
 import com.android.settings.net.UidDetail;
 import com.android.settings.net.UidDetailProvider;
@@ -144,6 +143,7 @@
 import com.android.settings.widget.ChartDataUsageView;
 import com.android.settings.widget.ChartDataUsageView.DataUsageChartListener;
 import com.android.settings.widget.ChartNetworkSeriesView;
+import com.android.settingslib.NetworkPolicyEditor;
 import com.google.android.collect.Lists;
 
 import libcore.util.Objects;