[MS16.1] Prepare APIs for replacing getNetwork[Total|Uid]Bytes

These internal methods are used in MultipathPolicyTracker and
NetworkPolicyManagementService. getNetworkTotalBytes is used
to query total bytes regarding to the specified NetworkPolicy,
to see how much data quota is used. getNetworkUidBytes is used
to find the app to blame for rapid data usage.

These methods needs to be replaced by public APIs in follow-up
patches.

Test: TH
Bug: 204830222
Change-Id: Iec9cc7a07397ec2bbc6c3d2559fc3680b149cb8a

framework-t/src/android/app/usage/NetworkStatsManager.java

@@ -170,16 +170,44 @@ public class NetworkStatsManager {
         }
     }
 
-    /** @hide */
+    /**
-    public Bucket querySummaryForDevice(NetworkTemplate template,
+     * Query network usage statistics summaries.
-            long startTime, long endTime) throws SecurityException, RemoteException {
+     *
-        Bucket bucket = null;
+     * Result is summarised data usage for the whole
-        NetworkStats stats = new NetworkStats(mContext, template, mFlags, startTime, endTime,
+     * device. Result is a single Bucket aggregated over time, state, uid, tag, metered, and
-                mService);
+     * roaming. This means the bucket's start and end timestamp will be the same as the
-        bucket = stats.getDeviceSummaryForNetwork();
+     * 'startTime' and 'endTime' arguments. State is going to be
-
+     * {@link NetworkStats.Bucket#STATE_ALL}, uid {@link NetworkStats.Bucket#UID_ALL},
-        stats.close();
+     * tag {@link NetworkStats.Bucket#TAG_NONE},
-        return bucket;
+     * default network {@link NetworkStats.Bucket#DEFAULT_NETWORK_ALL},
+     * metered {@link NetworkStats.Bucket#METERED_ALL},
+     * and roaming {@link NetworkStats.Bucket#ROAMING_ALL}.
+     * This may take a long time, and apps should avoid calling this on their main thread.
+     *
+     * @param template Template used to match networks. See {@link NetworkTemplate}.
+     * @param startTime Start of period, in milliseconds since the Unix epoch, see
+     *            {@link java.lang.System#currentTimeMillis}.
+     * @param endTime End of period, in milliseconds since the Unix epoch, see
+     *            {@link java.lang.System#currentTimeMillis}.
+     * @return Bucket Summarised data usage.
+     *
+     * @hide
+     */
+    @NonNull
+    @WorkerThread
+    // @SystemApi(client = MODULE_LIBRARIES)
+    public Bucket querySummaryForDevice(@NonNull NetworkTemplate template,
+            long startTime, long endTime) {
+        try {
+            NetworkStats stats =
+                    new NetworkStats(mContext, template, mFlags, startTime, endTime, mService);
+            Bucket bucket = stats.getDeviceSummaryForNetwork();
+            stats.close();
+            return bucket;
+        } catch (RemoteException e) {
+            e.rethrowFromSystemServer();
+        }
+        return null; // To make the compiler happy.
     }
 
     /**
@@ -323,14 +351,37 @@ public class NetworkStatsManager {
         return querySummary(template, startTime, endTime);
     }
 
-    /** @hide */
+    /**
-    public NetworkStats querySummary(NetworkTemplate template, long startTime,
+     * Query network usage statistics summaries.
-            long endTime) throws SecurityException, RemoteException {
+     *
-        NetworkStats result;
+     * The results will only include traffic made by UIDs belonging to the calling user profile.
-        result = new NetworkStats(mContext, template, mFlags, startTime, endTime, mService);
+     * The results are aggregated over time, so that all buckets will have the same start and
-        result.startSummaryEnumeration();
+     * end timestamps as the passed arguments. Not aggregated over state, uid, default network,
-
+     * metered, or roaming.
-        return result;
+     * This may take a long time, and apps should avoid calling this on their main thread.
+     *
+     * @param template Template used to match networks. See {@link NetworkTemplate}.
+     * @param startTime Start of period, in milliseconds since the Unix epoch, see
+     *            {@link java.lang.System#currentTimeMillis}.
+     * @param endTime End of period, in milliseconds since the Unix epoch, see
+     *            {@link java.lang.System#currentTimeMillis}.
+     * @return Statistics which is described above.
+     * @hide
+     */
+    @Nullable
+    // @SystemApi(client = MODULE_LIBRARIES)
+    @WorkerThread
+    public NetworkStats querySummary(@NonNull NetworkTemplate template, long startTime,
+            long endTime) throws SecurityException {
+        try {
+            NetworkStats result =
+                    new NetworkStats(mContext, template, mFlags, startTime, endTime, mService);
+            result.startSummaryEnumeration();
+            return result;
+        } catch (RemoteException e) {
+            e.rethrowFromSystemServer();
+        }
+        return null; // To make the compiler happy.
     }
 
     /**