Remove backup agent from AOSP Android Keyboard

Bug: 4590284
Change-Id: I22f0e42cb898d20dfc2c4506493bf48170ce7b04
diff --git a/java/AndroidManifest.xml b/java/AndroidManifest.xml
index 8ffa29d..5f64768 100644
--- a/java/AndroidManifest.xml
+++ b/java/AndroidManifest.xml
@@ -27,7 +27,6 @@
 
     <application android:label="@string/aosp_android_keyboard_ime_name"
             android:icon="@mipmap/ic_ime_settings"
-            android:backupAgent="BackupAgent"
             android:killAfterRestore="false"
             android:supportsRtl="true">