title: How to change Android O / Oreo / api 26 app language
body: <p>I want to change the language of the app and this works fine until API 26.</p>
  
  <p>For api > 25 I put <code>Locale.setDefault(Locale.Category.DISPLAY, mynewlanglocale);</code> before <code>setContentView(R.layout.activity_main);</code> but nothing changes.</p>
  
  <p>The <a href="https://developer.android.com/reference/java/util/Locale.html#setDefault(java.util.Locale.Category,%20java.util.Locale)" rel="noreferrer">docs</a> don't explain too much about this.</p>