android: Add template to export sandboxed service

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 e06efab5062162208581e3077aaba24c49a7e6f1..6e84b18bf772d180960749fe82eeea46013eef9d 100644
--- a/chrome/android/java/AndroidManifest.xml
+++ b/chrome/android/java/AndroidManifest.xml
@@ -624,7 +624,11 @@ by a child template that "extends" this file.
             android:process=":sandboxed_process{{ i }}"
             android:permission="{{ manifest_package }}.permission.CHILD_SERVICE"
             android:isolatedProcess="true"
-            android:exported="false" />
+            android:exported="{{sandboxed_service_exported|default(false)}}"
+            {% if (sandboxed_service_exported|default(false)) == 'true' %}
+            tools:ignore="ExportedService"
+            {% endif %}
+            {{sandboxed_service_extra_flags|default('')}} />
         {% endfor %}
 
         {% set num_privileged_services = 3 %}