UpdateEngine: Add perf mode binder interface

Change-Id: I3146ea0eb9477129fa2e490fe9b149ad48ec0fba
diff --git a/core/java/android/os/UpdateEngine.java b/core/java/android/os/UpdateEngine.java
index 5a48242..74a8f40 100644
--- a/core/java/android/os/UpdateEngine.java
+++ b/core/java/android/os/UpdateEngine.java
@@ -425,6 +425,17 @@
     }
 
     /**
+     * @hide
+     */
+    public void setPerformanceMode(boolean enable) {
+        try {
+            mUpdateEngine.setPerformanceMode(enable);
+        } catch (RemoteException e) {
+            throw e.rethrowFromSystemServer();
+        }
+    }
+
+    /**
      * Unbinds the last bound callback function.
      */
     public boolean unbind() {