[MS68.1] Register usage callback from NetworkPolicyManagerService

Use usage callback to replace the need of intent receiver.

Test: atest TrafficStatsTest NetworkUsageStatsTest FrameworksNetTests
Bug: 204830222
Change-Id: I40967c2b6c86d25c7db93e6d3a4908b72ed76154

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

@@ -729,7 +729,8 @@ public class NetworkStatsManager {
      * {@link #unregisterUsageCallback} is called.
      *
      * @param template Template used to match networks. See {@link NetworkTemplate}.
-     * @param thresholdBytes Threshold in bytes to be notified on.
+     * @param thresholdBytes Threshold in bytes to be notified on. The provided value that lower
+     *                       than 2MiB will be clamped for non-privileged callers.
      * @param executor The executor on which callback will be invoked. The provided {@link Executor}
      *                 must run callback sequentially, otherwise the order of callbacks cannot be
      *                 guaranteed.