Fix cannot create Nat-T keepalive on mobile data

Currently phone process fail to unparcel NattKeepalivePacketData
since it is not in framework. Moves NattKeepalivePacketData to
framework to make it can be utilized by telephony.

This change also removes the error feedback triggered by calling
add keepalive packet filter to an unsupported network agent. This
is misinterpreted by KeepaliveTracker that start keepalive is
failing.

Bug: 134048171
Test: 1. atest android.net.cts.ConnectivityManagerTest#testSocketKeepaliveLimitTelephony
      2. atest android.net.cts.ConnectivityManagerTest
      3. atest FrameworksNetTests
      4. atest FrameworksTelephonyTests

Merged-In: If630d5b339aa722717258c721daa8ead8c431e2d
Change-Id: Ic0f168be6f5a6263a5e0565b6381dcb5c645660f
(cherry picked from commit 9ede677bb2c081ccdc41c8c3c19c949114bcc138)

core/java/android/net/NattKeepalivePacketData.java

@@ -1,5 +1,5 @@
 /*
- * Copyright (C) 2018 The Android Open Source Project
+ * Copyright (C) 2019 The Android Open Source Project
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -19,9 +19,9 @@ package android.net;
 import static android.net.SocketKeepalive.ERROR_INVALID_IP_ADDRESS;
 import static android.net.SocketKeepalive.ERROR_INVALID_PORT;
 
-import android.annotation.NonNull;
 import android.net.SocketKeepalive.InvalidPacketException;
 import android.net.util.IpUtils;
+import android.os.Parcel;
 import android.os.Parcelable;
 import android.system.OsConstants;
 
@@ -79,17 +79,40 @@ public final class NattKeepalivePacketData extends KeepalivePacketData implement
         return new NattKeepalivePacketData(srcAddress, srcPort, dstAddress, dstPort, buf.array());
     }
 
-     /**
-     * Convert this NattKeepalivePacketData to a NattKeepalivePacketDataParcelable.
-     */
-    @NonNull
-    public NattKeepalivePacketDataParcelable toStableParcelable() {
-        final NattKeepalivePacketDataParcelable parcel = new NattKeepalivePacketDataParcelable();
-
-        parcel.srcAddress = srcAddress.getAddress();
-        parcel.srcPort = srcPort;
-        parcel.dstAddress = dstAddress.getAddress();
-        parcel.dstPort = dstPort;
-        return parcel;
+    /** Parcelable Implementation */
+    public int describeContents() {
+        return 0;
     }
+
+    /** Write to parcel */
+    public void writeToParcel(Parcel out, int flags) {
+        out.writeString(srcAddress.getHostAddress());
+        out.writeString(dstAddress.getHostAddress());
+        out.writeInt(srcPort);
+        out.writeInt(dstPort);
+    }
+
+    /** Parcelable Creator */
+    public static final Parcelable.Creator<NattKeepalivePacketData> CREATOR =
+            new Parcelable.Creator<NattKeepalivePacketData>() {
+                public NattKeepalivePacketData createFromParcel(Parcel in) {
+                    final InetAddress srcAddress =
+                            InetAddresses.parseNumericAddress(in.readString());
+                    final InetAddress dstAddress =
+                            InetAddresses.parseNumericAddress(in.readString());
+                    final int srcPort = in.readInt();
+                    final int dstPort = in.readInt();
+                    try {
+                        return NattKeepalivePacketData.nattKeepalivePacket(srcAddress, srcPort,
+                                    dstAddress, dstPort);
+                    } catch (InvalidPacketException e) {
+                        throw new IllegalArgumentException(
+                                "Invalid NAT-T keepalive data: " + e.error);
+                    }
+                }
+
+                public NattKeepalivePacketData[] newArray(int size) {
+                    return new NattKeepalivePacketData[size];
+                }
+            };
 }

core/java/android/net/NetworkAgent.java

@@ -511,7 +511,6 @@ public abstract class NetworkAgent extends Handler {
      * override this method.
      */
     protected void addKeepalivePacketFilter(Message msg) {
-        onSocketKeepaliveEvent(msg.arg1, SocketKeepalive.ERROR_UNSUPPORTED);
     }
 
     /**
@@ -520,7 +519,6 @@ public abstract class NetworkAgent extends Handler {
      * must override this method.
      */
     protected void removeKeepalivePacketFilter(Message msg) {
-        onSocketKeepaliveEvent(msg.arg1, SocketKeepalive.ERROR_UNSUPPORTED);
     }
 
     /**

services/core/java/com/android/server/connectivity/KeepaliveTracker.java

@@ -216,6 +216,7 @@ public class KeepaliveTracker {
 
         public String toString() {
             return "KeepaliveInfo ["
+                    + " type=" + mType
                     + " network=" + mNai.network
                     + " startedState=" + startedStateString(mStartedState)
                     + " "