Revert "Prevent native_init from starting TrafficController"

We are ready to remove traffic controller from netd, so
TrafficController::start() should be called from the system server.

This reverts commit c2984fdc.

Test: atest FrameworksNetTests FrameworksNetIntegrationTests
CtsNetTestCases:android.net.TrafficStatsTest NetworkUsageStatsTest
CtsHostsideNetworkTests

Change-Id: Ic324ad0c064271977ab35d7f55badee00098e196

service/jni/com_android_server_BpfNetMaps.cpp

@@ -39,8 +39,7 @@ static android::net::TrafficController mTc;
 namespace android {
 
 static void native_init(JNIEnv* env, jobject clazz) {
-  // start is still being called by netd
-  Status status = mTc.initMaps();
+  Status status = mTc.start();
    if (!isOk(status)) {
     ALOGE("%s failed", __func__);
   }

service/native/include/TrafficController.h

@@ -32,22 +32,14 @@ namespace net {
 using netdutils::StatusOr;
 
 class TrafficController {
-    // TODO: marking this private for right now, as start is already called by
-    // netd. start() calls initMaps(), initPrograms(), and sets up the socket
-    // destroy listener. Both initPrograms() and setting up the socket destroy
-    // listener should only be done once.
+  public:
+    static constexpr char DUMP_KEYWORD[] = "trafficcontroller";
+
     /*
      * Initialize the whole controller
      */
     netdutils::Status start();
 
-  public:
-    static constexpr char DUMP_KEYWORD[] = "trafficcontroller";
-
-    // TODO: marking this public for right now, as start() is already called by
-    // netd.
-    netdutils::Status initMaps() EXCLUDES(mMutex);
-
     int setCounterSet(int counterSetNum, uid_t uid, uid_t callingUid) EXCLUDES(mMutex);
 
     /*
@@ -195,6 +187,8 @@ class TrafficController {
 
     std::mutex mMutex;
 
+    netdutils::Status initMaps() EXCLUDES(mMutex);
+
     // Keep track of uids that have permission UPDATE_DEVICE_STATS so we don't
     // need to call back to system server for permission check.
     std::set<uid_t> mPrivilegedUser GUARDED_BY(mMutex);