Disable access to secondary dex files.

base/android/java/templates/BuildConfig.template

Index: base/android/java/templates/BuildConfig.template
diff --git a/base/android/java/templates/BuildConfig.template b/base/android/java/templates/BuildConfig.template
index 16f02f6a6cf7daf43ec8db98f43303a435d1f3bf..edfc8804eada4937495d46448404f7a1e8a37106 100644
--- a/base/android/java/templates/BuildConfig.template
+++ b/base/android/java/templates/BuildConfig.template
@@ -22,6 +22,19 @@ public class BuildConfig {
 #endif
     }
 
+    /** Whether this target was built for an official build or not.
+     *
+     *  This has to be a function instead of a static final boolean s.t. the initial false value
+     *  doesn't get optimized into {@link ChromeApplication} at base_java compile time.
+     */
+    public static boolean isOfficialBuild() {
+#if defined(IS_OFFICIAL_BUILD)
+        return true;
+#else
+        return false;
+#endif
+    }
+
     // DCHECK_IS_ON does not change between targets, can be final and optimized out.
 #if defined(_DCHECK_IS_ON)
     public static final boolean DCHECK_IS_ON = true;