title: java String.Format("%02d") produces strange unicode characters
body: <p>I'm doing exactly this:</p>
  
  <pre><code>    int level = ...;//some value from game
      Analytics.newDesignEvent(String.format("level_end:%02d:win", level));
  </code></pre>
  
  <p>And I've found that some devices send strings with unicode symbols such as "٠١":</p>
  
  <p><strong>level_end:٠١:win</strong></p>
  
  <p>I've tried to reproduce it in my environment, but String.format worked ok with any integer value.
  May this be somehow caused by specific locales? Why else this can happen?</p>
  
  <p>Updt2:
  I didn't find any info whether string + int/float/etc. concantenation also take locale into consideration. Do smbd happen to know?</p>