Revert of Implement Android key/value backup

chrome/android/java/AndroidManifest.xml

Index: chrome/android/java/AndroidManifest.xml
diff --git a/chrome/android/java/AndroidManifest.xml b/chrome/android/java/AndroidManifest.xml
index 7a53df6941344d5b3fb07e46d6d639753e8e8569..72f556a48ff71d5a74ba7b298d7d29f45cfee3e7 100644
--- a/chrome/android/java/AndroidManifest.xml
+++ b/chrome/android/java/AndroidManifest.xml
@@ -110,16 +110,15 @@
         android:icon="@mipmap/app_icon"
         android:label="@string/app_name"
         android:largeHeap="false"
+        android:allowBackup="false"
         android:manageSpaceActivity="@string/manage_space_activity"
-        android:supportsRtl="true"
-        {% if backup_key is defined %}
-        android:allowBackup="true"
-        android:backupAgent="org.chromium.chrome.browser.ChromeBackupAgent"
+        android:fullBackupContent="@xml/chromebackupscheme"
         android:fullBackupOnly="false"
         android:restoreAnyVersion="true"
-        {% else %}
-        android:allowBackup="false"
-        {% endif %}
+        {% block android_backup_agent %}
+        android:backupAgent="org.chromium.chrome.browser.ChromeBackupAgent"
+        {% endblock %}
+        android:supportsRtl="true"
         {% if target_sdk_version|int >= 24 %}
         android:networkSecurityConfig="@xml/network_security_config"
         {% endif %}
@@ -134,12 +133,6 @@
             android:value="singleTask" />
         <meta-data android:name="com.samsung.android.sdk.multiwindow.penwindow.enable"
             android:value="true"/>
-
-        {% if backup_key is defined %}
-        <!-- Backup keys are channel dependent -->
-        <meta-data android:name="com.google.android.backup.api_key"
-            android:value="{{ backup_key }}" />
-        {% endif %}
 
         {% if channel in ['dev', 'canary', 'default'] %}
         <meta-data android:name="com.sec.android.support.multiwindow" android:value="true" />