API CHANGE: remove obsolete constants and hide some methods

This change removes some unused constants from BackupDataOutput
and hides a few methods that do not actually need to be exposed.

Change-Id: I47a9a107a5b58f4d53b5a2fcf9b73a765b1c5dd8
diff --git a/api/current.xml b/api/current.xml
index a2063b5..8cffff1b 100644
--- a/api/current.xml
+++ b/api/current.xml
@@ -27062,19 +27062,6 @@
  deprecated="not deprecated"
  visibility="public"
 >
-<method name="setKeyPrefix"
- return="void"
- abstract="false"
- native="false"
- synchronized="false"
- static="false"
- final="false"
- deprecated="not deprecated"
- visibility="public"
->
-<parameter name="keyPrefix" type="java.lang.String">
-</parameter>
-</method>
 <method name="writeEntityData"
  return="int"
  abstract="false"
@@ -27109,28 +27096,6 @@
 <exception name="IOException" type="java.io.IOException">
 </exception>
 </method>
-<field name="OP_DELETE"
- type="int"
- transient="false"
- volatile="false"
- value="2"
- static="true"
- final="true"
- deprecated="not deprecated"
- visibility="public"
->
-</field>
-<field name="OP_UPDATE"
- type="int"
- transient="false"
- volatile="false"
- value="1"
- static="true"
- final="true"
- deprecated="not deprecated"
- visibility="public"
->
-</field>
 </class>
 <interface name="BackupHelper"
  abstract="true"
diff --git a/core/java/android/app/backup/BackupDataOutput.java b/core/java/android/app/backup/BackupDataOutput.java
index 53b1d46..3767797 100644
--- a/core/java/android/app/backup/BackupDataOutput.java
+++ b/core/java/android/app/backup/BackupDataOutput.java
@@ -25,9 +25,6 @@
 public class BackupDataOutput {
     int mBackupWriter;
 
-    public static final int OP_UPDATE = 1;
-    public static final int OP_DELETE = 2;
-
     /** @hide */
     public BackupDataOutput(FileDescriptor fd) {
         if (fd == null) throw new NullPointerException();
@@ -71,6 +68,7 @@
         }
     }
 
+    /** @hide */
     public void setKeyPrefix(String keyPrefix) {
         setKeyPrefix_native(mBackupWriter, keyPrefix);
     }