Disable paddles for DOM Distiller.

Currently paddles show up when distilling a web page. This CL disables
that part of the feature, to ensure no paddles show up.

BUG=418240

Review URL: https://codereview.chromium.org/611463004

Cr-Commit-Position: refs/heads/master@{#297049}

chrome/android/java/src/org/chromium/chrome/browser/dom_distiller/DomDistillerFeedbackReporter.java

@@ -45,7 +45,7 @@ public final class DomDistillerFeedbackReporter implements
      * @return whether the DOM Distiller feature is enabled.
      */
     public static boolean isEnabled() {
-        return nativeIsEnabled();
+        return false;
     }
 
     /**