Revert "Pivot network statistics to use DataInput/Output."

This reverts commit 1b4f0a409db397bcf877f36edcf15ed16e801d96.

Reason for revert: FastDataInput/Output is hidden and cannot be used in mainline module.

Test: TH
Bug: 204830222
Change-Id: I8cfa435bb6233818adb9cc99dadeeb06a03443d5
diff --git a/framework-t/src/android/net/NetworkStatsCollection.java b/framework-t/src/android/net/NetworkStatsCollection.java
index 7935d28..9f9d73f 100644
--- a/framework-t/src/android/net/NetworkStatsCollection.java
+++ b/framework-t/src/android/net/NetworkStatsCollection.java
@@ -46,8 +46,6 @@
 import android.util.proto.ProtoOutputStream;
 
 import com.android.internal.annotations.VisibleForTesting;
-import com.android.internal.util.FastDataInput;
-import com.android.internal.util.FastDataOutput;
 import com.android.internal.util.FileRotator;
 import com.android.net.module.util.CollectionUtils;
 import com.android.net.module.util.NetworkStatsUtils;
@@ -58,6 +56,7 @@
 import java.io.DataInput;
 import java.io.DataInputStream;
 import java.io.DataOutput;
+import java.io.DataOutputStream;
 import java.io.File;
 import java.io.FileNotFoundException;
 import java.io.IOException;
@@ -83,9 +82,6 @@
     /** File header magic number: "ANET" */
     private static final int FILE_MAGIC = 0x414E4554;
 
-    /** Default buffer size from BufferedInputStream */
-    private static final int BUFFER_SIZE = 8192;
-
     private static final int VERSION_NETWORK_INIT = 1;
 
     private static final int VERSION_UID_INIT = 1;
@@ -439,8 +435,7 @@
 
     @Override
     public void read(InputStream in) throws IOException {
-        final FastDataInput dataIn = new FastDataInput(in, BUFFER_SIZE);
-        read(dataIn);
+        read((DataInput) new DataInputStream(in));
     }
 
     private void read(DataInput in) throws IOException {
@@ -479,9 +474,8 @@
 
     @Override
     public void write(OutputStream out) throws IOException {
-        final FastDataOutput dataOut = new FastDataOutput(out, BUFFER_SIZE);
-        write(dataOut);
-        dataOut.flush();
+        write((DataOutput) new DataOutputStream(out));
+        out.flush();
     }
 
     private void write(DataOutput out) throws IOException {