Use multidex capable application for chrome_public_test_apk.

chrome/test/android/javatests/src/org/chromium/chrome/test/partnercustomizations/TestPartnerBrowserCustomizationsProvider.java

 // Copyright 2015 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 package org.chromium.chrome.test.partnercustomizations;
 
 import android.content.ContentProvider;
 import android.content.ContentValues;
 import android.content.Context;
 import android.content.UriMatcher;
 import android.content.pm.ProviderInfo;
 import android.database.Cursor;
 import android.database.MatrixCursor;
 import android.net.Uri;
 import android.os.Bundle;
 import android.text.TextUtils;
 import android.util.Log;
 
+import org.chromium.base.annotations.MainDex;
+
 /**
  * PartnerBrowserCustomizationsProvider example for testing.
  * Note: if you move or rename this class, make sure you have also updated AndroidManifest.xml.
  */
+@MainDex
 public class TestPartnerBrowserCustomizationsProvider extends ContentProvider {
     protected String mTag = TestPartnerBrowserCustomizationsProvider.class.getSimpleName();
 
     public static final String HOMEPAGE_URI = "http://127.0.0.1:8000/foo.html";
     public static final String INCOGNITO_MODE_DISABLED_KEY = "disableincognitomode";
     public static final String BOOKMARKS_EDITING_DISABLED_KEY = "disablebookmarksediting";
 
     protected static final int URI_MATCH_HOMEPAGE = 1001;
     protected static final int URI_MATCH_DISABLE_INCOGNITO_MODE = 1002;
     protected static final int URI_MATCH_DISABLE_BOOKMARKS_EDITING = 1003;
@@ skipping 97 matching lines @@
     public int delete(Uri uri, String selection, String[] selectionArgs) {
         throw new UnsupportedOperationException();
     }
 
     @Override
     public int update(Uri uri, ContentValues values, String selection, String[] selectionArgs) {
         throw new UnsupportedOperationException();
     }
 
 }