title: call requires api level 24 (current min is 21) new android.icu.text.DecimalFormat
body: <p>sorry I'm new how do I call this in a older API or ?
  getting this warning call requires api level 24 (current min is 21) new android.icu.text.DecimalFormat</p>
  
  <pre><code>public static String roundThousandsIntoK(Number number) {
      char[] suffix = {' ', 'k', 'M', 'B', 'T', 'P', 'E'};
      long numValue = number.longValue();
      int value = (int) Math.floor(Math.log10(numValue));
      int base = value / 3;
      if (value &gt;= 3 &amp;&amp; base &lt; suffix.length) {
          return new DecimalFormat("#0.0").format(numValue / Math.pow(10, base * 3)) + suffix[base];
      } else {
          return new DecimalFormat("#,##0").format(numValue);
      }
  }
  </code></pre>