title: Kotlin Extension Functions suddenly require api level 24
body: <p>I just noticed this lint error:</p>
  
  <blockquote>
    <p>Call requires API Level 24 (current min is 19) java.util.map#foreach</p>
  </blockquote>
  
  <p>when I use the extension function forEach on a MutableMap in Kotlin.
  This didn't happen when I wrote the line, but its there now.
  And I'm not seeing this error on my other machine.</p>