Update to newer Android Lint and suppress new Lint errors

chrome/android/java/src/org/chromium/chrome/browser/signin/SigninHelper.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.browser.signin;
 
 import android.accounts.Account;
+import android.annotation.SuppressLint;
 import android.content.Context;
 import android.os.AsyncTask;
 
 import com.google.android.gms.auth.AccountChangeEvent;
 import com.google.android.gms.auth.GoogleAuthException;
 import com.google.android.gms.auth.GoogleAuthUtil;
 
 import org.chromium.base.ContextUtils;
 import org.chromium.base.Log;
 import org.chromium.base.VisibleForTesting;
@@ skipping 28 matching lines @@
 
     // Key to the shared pref that holds the new account's name if the currently signed
     // in account has been renamed.
     private static final String ACCOUNT_RENAMED_PREFS_KEY = "prefs_sync_account_renamed";
 
     // Key to the shared pref that holds the last read index of all the account changed
     // events of the current signed in account.
     private static final String ACCOUNT_RENAME_EVENT_INDEX_PREFS_KEY =
             "prefs_sync_account_rename_event_index";
 
+    @SuppressLint("StaticFieldLeak")
     private static SigninHelper sInstance;
 
     /**
      * Retrieve more detailed information from account changed intents.
      */
     public static interface AccountChangeEventChecker {
         public List<String> getAccountChangeEvents(
                 Context context, int index, String accountName);
     }
 
@@ skipping 306 matching lines @@
                 .getBoolean(ACCOUNTS_CHANGED_PREFS_KEY, false)) {
             // Clear the value in prefs.
             ContextUtils.getAppSharedPreferences()
                     .edit().putBoolean(ACCOUNTS_CHANGED_PREFS_KEY, false).apply();
             return true;
         } else {
             return false;
         }
     }
 }