Make TokenBucket available to the network stack

Bug: b/144826001

Test: Build Pass: OK
Test: Power ON/OFF: OK
Test: Verify CPU loading improvement: OK

Change-Id: I75d55c3e53fce57e50533dc74af3381a6cee4b96

Android.bp

@@ -603,6 +603,7 @@ filegroup {
         "core/java/com/android/internal/util/StateMachine.java",
         "core/java/com/android/internal/util/TrafficStatsConstants.java",
         "core/java/com/android/internal/util/WakeupMessage.java",
+        "core/java/com/android/internal/util/TokenBucket.java",
         "core/java/android/net/shared/*.java",
     ],
 }