[Android] Incorporate findbugs into android builds.

build/android/findbugs_filter/findbugs_exclude.xml

 <?xml version="1.0" encoding="UTF-8"?>
 <!--
   Copyright (c) 2012 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.
 -->
 
 <!--
 Documentation: http://findbugs.sourceforge.net/manual/filter.html
 In particular, ~ at the start of a string means it's a regex.
 -->
 <FindBugsFilter>
   <!-- Skip the generated resource classes (including nested classes). -->
   <Match>
     <Class name="~org\.chromium\..*\.R(\$\w+)?" />
   </Match>
   <Match>
     <Class name="~org\.chromium\..*\.Manifest(\$\w+)?" />
   </Match>
-  <!-- Ignore "reliance on default String encoding" warnings, as we're not multi-platform -->
   <Match>
     <Class name="~org\.chromium\.chrome\.browser\.ChromiumApplication.*" />
     <Method name="onCancel" />
     <Bug code="Dm" />
   </Match>
   <Match>
     <Class name="~org\.chromium\.chrome\.browser\.ChromiumApplication.*" />
     <Method name="onClick" />
     <Bug code="Dm" />
   </Match>
+  <Bug pattern="DM_STRING_CTOR" />
+  <!-- Ignore "reliance on default String encoding" warnings, as we're not multi-platform -->
   <Bug pattern="DM_DEFAULT_ENCODING" />
   <!-- Ignore bugs that are often false-positives in test code -->
   <Match>
     <Class name="~org\.chromium\..*Test(\$\w+)?" />
     <Or>
       <Bug code="DLS,UrF" />
       <Bug pattern="DM_GC" />
     </Or>
   </Match>
   <!--
   crbug.com/449101
   Ignore findbugs plugin test cases.
   -->
   <Match>
     <Or>
       <Class name="~org\.chromium\.tools\.findbugs\.plugin\.SimpleSynchronizedMethod" />
       <Class name="~org\.chromium\.tools\.findbugs\.plugin\.SimpleSynchronizedStaticMethod" />
       <Class name="~org\.chromium\.tools\.findbugs\.plugin\.SimpleSynchronizedThis" />
     </Or>
   </Match>
 </FindBugsFilter>