Update to newer Android Lint and suppress new Lint errors

chrome/test/android/javatests/src/org/chromium/chrome/test/util/browser/signin/SigninTestUtil.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.util.browser.signin;
 
 import android.accounts.Account;
+import android.annotation.SuppressLint;
 import android.app.Instrumentation;
 import android.content.Context;
 
 import org.chromium.base.ContextUtils;
 import org.chromium.base.ThreadUtils;
 import org.chromium.chrome.browser.init.ProcessInitializationHandler;
 import org.chromium.chrome.browser.signin.AccountIdProvider;
 import org.chromium.chrome.browser.signin.AccountTrackerService;
 import org.chromium.chrome.browser.signin.OAuth2TokenService;
 import org.chromium.components.signin.AccountManagerHelper;
 import org.chromium.components.signin.ChromeSigninController;
 import org.chromium.components.signin.test.util.AccountHolder;
 import org.chromium.components.signin.test.util.FakeAccountManagerDelegate;
 
 import java.util.HashSet;
 
 /**
  * Utility class for test signin functionality.
  */
 public final class SigninTestUtil {
     private static final String TAG = "Signin";
 
     private static final String DEFAULT_ACCOUNT = "test@gmail.com";
 
+    @SuppressLint("StaticFieldLeak")
     private static Context sContext;
+    @SuppressLint("StaticFieldLeak")
     private static FakeAccountManagerDelegate sAccountManager;
 
     /**
      * Sets up the test authentication environment.
      *
      * This must be called before native is loaded.
      */
     public static void setUpAuthForTest(Instrumentation instrumentation) {
         assert sContext == null;
         sContext = instrumentation.getTargetContext();
@@ skipping 96 matching lines @@
         // Clear cached signed account name and accounts list.
         ChromeSigninController.get().setSignedInAccountName(null);
         ContextUtils.getAppSharedPreferences()
                 .edit()
                 .putStringSet(OAuth2TokenService.STORED_ACCOUNTS_KEY, new HashSet<String>())
                 .apply();
     }
 
     private SigninTestUtil() {}
 }