services.net: Add a static library needed by wifi module

Add a new static library that compiles against system_current which
includes all the parts needed by the wifi mainline module.

Also,
a) Refactored TcpKeepalivePacketData to use public APIs. The parcel
read/write methods in the base class are @hide and they're not used by
the other child class (NatKeepalivePacketData). So, remove the @hide
method from base class and use it direcly in the child class.

Bug: 145825329
Test: Device boots up & connects to wifi networks.
Change-Id: Ifde69b579cfe5b813766f676acb10e436e64a44c
Merged-In: Ifde69b579cfe5b813766f676acb10e436e64a44c
diff --git a/core/java/android/net/KeepalivePacketData.java b/core/java/android/net/KeepalivePacketData.java
index 2b8b7e6..6c0ba2f 100644
--- a/core/java/android/net/KeepalivePacketData.java
+++ b/core/java/android/net/KeepalivePacketData.java
@@ -22,7 +22,6 @@
 import android.annotation.NonNull;
 import android.annotation.SystemApi;
 import android.net.util.IpUtils;
-import android.os.Parcel;
 import android.util.Log;
 
 import java.net.InetAddress;
@@ -30,7 +29,6 @@
 /**
  * Represents the actual packets that are sent by the
  * {@link android.net.SocketKeepalive} API.
- *
  * @hide
  */
 @SystemApi
@@ -54,6 +52,9 @@
     /** Packet data. A raw byte string of packet data, not including the link-layer header. */
     private final byte[] mPacket;
 
+    // Note: If you add new fields, please modify the parcelling code in the child classes.
+
+
     // This should only be constructed via static factory methods, such as
     // nattKeepalivePacket.
     /**
@@ -87,21 +88,4 @@
         return mPacket.clone();
     }
 
-    /** @hide */
-    public void writeToParcel(Parcel out, int flags) {
-        out.writeString(srcAddress.getHostAddress());
-        out.writeString(dstAddress.getHostAddress());
-        out.writeInt(srcPort);
-        out.writeInt(dstPort);
-        out.writeByteArray(mPacket);
-    }
-
-    /** @hide */
-    protected KeepalivePacketData(Parcel in) {
-        srcAddress = NetworkUtils.numericToInetAddress(in.readString());
-        dstAddress = NetworkUtils.numericToInetAddress(in.readString());
-        srcPort = in.readInt();
-        dstPort = in.readInt();
-        mPacket = in.createByteArray();
-    }
 }